Organic light emitting materials

ABSTRACT

Phosphorescent iridium complexes comprising multi-alkyl-substituted aza-DBF and 2-phenylpyridine ligands is disclosed. These complexes are useful as emitters for phosphorescent OLEDs.

PARTIES TO A JOINT RESEARCH AGREEMENT

The claimed invention was made by, on behalf of, and/or in connectionwith one or more of the following parties to a joint universitycorporation research agreement: The Regents of the University ofMichigan, Princeton University, University of Southern California, andUniversal Display Corporation. The agreement was in effect on and beforethe date the claimed invention was made, and the claimed invention wasmade as a result of activities undertaken within the scope of theagreement.

FIELD OF THE INVENTION

The present invention relates to compounds for use as phosphorescentemitters and devices, such as organic light emitting diodes, includingthe same.

BACKGROUND

Opto-electronic devices that make use of organic materials are becomingincreasingly desirable for a number of reasons. Many of the materialsused to make such devices are relatively inexpensive, so organicopto-electronic devices have the potential for cost advantages overinorganic devices. In addition, the inherent properties of organicmaterials, such as their flexibility, may make them well suited forparticular applications such as fabrication on a flexible substrate.Examples of organic opto-electronic devices include organic lightemitting devices (OLEDs), organic phototransistors, organic photovoltaiccells, and organic photodetectors. For OLEDs, the organic materials mayhave performance advantages over conventional materials. For example,the wavelength at which an organic emissive layer emits light maygenerally be readily tuned with appropriate dopants.

OLEDs make use of thin organic films that emit light when voltage isapplied across the device. OLEDs are becoming an increasinglyinteresting technology for use in applications such as flat paneldisplays, illumination, and backlighting. Several OLED materials andconfigurations are described in U.S. Pat. Nos. 5,844,363, 6,303,238, and5,707,745, which are incorporated herein by reference in their entirety.

One application for phosphorescent emissive molecules is a full colordisplay. Industry standards for such a display call for pixels adaptedto emit particular colors, referred to as “saturated” colors. Inparticular, these standards call for saturated red, green, and bluepixels. Color may be measured using CIE coordinates, which are wellknown to the art.

One example of a green emissive molecule is tris(2-phenylpyridine)iridium, denoted Ir(ppy)₃, which has the following structure:

In this, and later figures herein, we depict the dative bond fromnitrogen to metal (here, Ir) as a straight line.

As used herein, the term “organic” includes polymeric materials as wellas small molecule organic materials that may be used to fabricateorganic opto-electronic devices. “Small molecule” refers to any organicmaterial that is not a polymer, and “small molecules” may actually bequite large. Small molecules may include repeat units in somecircumstances. For example, using a long chain alkyl group as asubstituent does not remove a molecule from the “small molecule” class.Small molecules may also be incorporated into polymers, for example as apendent group on a polymer backbone or as a part of the backbone. Smallmolecules may also serve as the core moiety of a dendrimer, whichconsists of a series of chemical shells built on the core moiety. Thecore moiety of a dendrimer may be a fluorescent or phosphorescent smallmolecule emitter. A dendrimer may be a “small molecule,” and it isbelieved that all dendrimers currently used in the field of OLEDs aresmall molecules.

As used herein, “top” means furthest away from the substrate, while“bottom” means closest to the substrate. Where a first layer isdescribed as “disposed over” a second layer, the first layer is disposedfurther away from substrate. There may be other layers between the firstand second layer, unless it is specified that the first layer is “incontact with” the second layer. For example, a cathode may be describedas “disposed over” an anode, even though there are various organiclayers in between.

As used herein, “solution processible” means capable of being dissolved,dispersed, or transported in and/or deposited from a liquid medium,either in solution or suspension form.

A ligand may be referred to as “photoactive” when it is believed thatthe ligand directly contributes to the photoactive properties of anemissive material. A ligand may be referred to as “ancillary” when it isbelieved that the ligand does not contribute to the photoactiveproperties of an emissive material, although an ancillary ligand mayalter the properties of a photoactive ligand.

As used herein, and as would be generally understood by one skilled inthe art, a first “Highest Occupied Molecular Orbital” (HOMO) or “LowestUnoccupied Molecular Orbital” (LUMO) energy level is “greater than” or“higher than” a second HOMO or LUMO energy level if the first energylevel is closer to the vacuum energy level. Since ionization potentials(IP) are measured as a negative energy relative to a vacuum level, ahigher HOMO energy level corresponds to an IP having a smaller absolutevalue (an IP that is less negative). Similarly, a higher LUMO energylevel corresponds to an electron affinity (EA) having a smaller absolutevalue (an EA that is less negative). On a conventional energy leveldiagram, with the vacuum level at the top, the LUMO energy level of amaterial is higher than the HOMO energy level of the same material. A“higher” HOMO or LUMO energy level appears closer to the top of such adiagram than a “lower” HOMO or LUMO energy level.

As used herein, and as would be generally understood by one skilled inthe art, a first work function is “greater than” or “higher than” asecond work function if the first work function has a higher absolutevalue. Because work functions are generally measured as negative numbersrelative to vacuum level, this means that a “higher” work function ismore negative. On a conventional energy level diagram, with the vacuumlevel at the top, a “higher” work function is illustrated as furtheraway from the vacuum level in the downward direction. Thus, thedefinitions of HOMO and LUMO energy levels follow a different conventionthan work functions.

More details on OLEDs, and the definitions described above, can be foundin U.S. Pat. No. 7,279,704, which is incorporated herein by reference inits entirety.

SUMMARY OF THE INVENTION

According to an embodiment, a compound having the formulaIr(L_(A))_(n)(L_(B))_(3-n), having the structure according to Formula Ishown below is disclosed:

In Formula I, R_(a), R_(b), and R_(c) each independently representmono-, di-, tri-, tetra-substitution, or no substitution;

wherein X is O, S, or Se;

wherein n is an integer from 1 to 3;

wherein R_(a), R_(b), and R_(c) are each independently selected from thegroup consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl,heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl,cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl,carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl,sulfonyl, phosphino, and combinations thereof;

wherein R¹, R², R³, and R⁴ are each independently selected from thegroup consisting of hydrogen, deuterium, aryl, alkyl, cycloalkyl, andcombinations thereof;

wherein at least two of R¹, R², R³, and R⁴ are alkyl, cycloalkyl, orcombinations thereof; and

wherein any adjacent substitutions in R¹ to R⁴ and R_(a) to R_(c) areoptionally linked together to form a ring.

According to another embodiment, a device comprising one or more organiclight emitting devices is also provided. At least one of the one or moreorganic light emitting devices can include an anode, a cathode, and anorganic layer, wherein the organic layer comprises the compound having aformula Ir(L_(A))_(n)(L_(B))_(3-n), having the structure according toFormula I disclosed herein. The device can be a consumer product, anelectronic component module, an organic light-emitting device, and/or alighting panel.

According to yet another embodiment, a formulation comprising thecompound having a formula Ir(L_(A))_(n)(L_(B))_(3-n), having thestructure according to Formula I disclosed herein disclosed.

The present disclosure provides iridium complexes comprisingmulti-alkyl-substituted aza-DBF and 2-phenylpyridine ligands that areuseful as emitters for phosphorescent OLEDs (PHOLEDs) by providingimproved device performance such as CIE color and lifetime, etc.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an organic light emitting device.

FIG. 2 shows an inverted organic light emitting device that does nothave a separate electron transport layer.

FIG. 3 shows Formula I of the disclosed inventive compound.

DETAILED DESCRIPTION

Generally, an OLED comprises at least one organic layer disposed betweenand electrically connected to an anode and a cathode. When a current isapplied, the anode injects holes and the cathode injects electrons intothe organic layer(s). The injected holes and electrons each migratetoward the oppositely charged electrode. When an electron and holelocalize on the same molecule, an “exciton,” which is a localizedelectron-hole pair having an excited energy state, is formed. Light isemitted when the exciton relaxes via a photoemissive mechanism. In somecases, the exciton may be localized on an excimer or an exciplex.Non-radiative mechanisms, such as thermal relaxation, may also occur,but are generally considered undesirable.

The initial OLEDs used emissive molecules that emitted light from theirsinglet states (“fluorescence”) as disclosed, for example, in U.S. Pat.No. 4,769,292, which is incorporated by reference in its entirety.Fluorescent emission generally occurs in a time frame of less than 10nanoseconds.

More recently, OLEDs having emissive materials that emit light fromtriplet states (“phosphorescence”) have been demonstrated. Baldo et al.,“Highly Efficient Phosphorescent Emission from OrganicElectroluminescent Devices,” Nature, vol. 395, 151-154, 1998;(“Baldo-I”) and Baldo et al., “Very high-efficiency green organiclight-emitting devices based on electrophosphorescence,” Appl. Phys.Lett., vol. 75, No. 3, 4-6 (1999) (“Baldo-II”), which are incorporatedby reference in their entireties. Phosphorescence is described in moredetail in U.S. Pat. No. 7,279,704 at cols. 5-6, which are incorporatedby reference.

FIG. 1 shows an organic light emitting device 100. The figures are notnecessarily drawn to scale. Device 100 may include a substrate 110, ananode 115, a hole injection layer 120, a hole transport layer 125, anelectron blocking layer 130, an emissive layer 135, a hole blockinglayer 140, an electron transport layer 145, an electron injection layer150, a protective layer 155, a cathode 160, and a barrier layer 170.Cathode 160 is a compound cathode having a first conductive layer 162and a second conductive layer 164. Device 100 may be fabricated bydepositing the layers described, in order. The properties and functionsof these various layers, as well as example materials, are described inmore detail in U.S. Pat. No. 7,279,704 at cols. 6-10, which areincorporated by reference.

More examples for each of these layers are available. For example, aflexible and transparent substrate-anode combination is disclosed inU.S. Pat. No. 5,844,363, which is incorporated by reference in itsentirety. An example of a p-doped hole transport layer is m-MTDATA dopedwith F₄-TCNQ at a molar ratio of 50:1, as disclosed in U.S. PatentApplication Publication No. 2003/0230980, which is incorporated byreference in its entirety. Examples of emissive and host materials aredisclosed in U.S. Pat. No. 6,303,238 to Thompson et al., which isincorporated by reference in its entirety. An example of an n-dopedelectron transport layer is BPhen doped with Li at a molar ratio of 1:1,as disclosed in U.S. Patent Application Publication No. 2003/0230980,which is incorporated by reference in its entirety. U.S. Pat. Nos.5,703,436 and 5,707,745, which are incorporated by reference in theirentireties, disclose examples of cathodes including compound cathodeshaving a thin layer of metal such as Mg:Ag with an overlyingtransparent, electrically-conductive, sputter-deposited ITO layer. Thetheory and use of blocking layers is described in more detail in U.S.Pat. No. 6,097,147 and U.S. Patent Application Publication No.2003/0230980, which are incorporated by reference in their entireties.Examples of injection layers are provided in U.S. Patent ApplicationPublication No. 2004/0174116, which is incorporated by reference in itsentirety. A description of protective layers may be found in U.S. PatentApplication Publication No. 2004/0174116, which is incorporated byreference in its entirety.

FIG. 2 shows an inverted OLED 200. The device includes a substrate 210,a cathode 215, an emissive layer 220, a hole transport layer 225, and ananode 230. Device 200 may be fabricated by depositing the layersdescribed, in order. Because the most common OLED configuration has acathode disposed over the anode, and device 200 has cathode 215 disposedunder anode 230, device 200 may be referred to as an “inverted” OLED.Materials similar to those described with respect to device 100 may beused in the corresponding layers of device 200. FIG. 2 provides oneexample of how some layers may be omitted from the structure of device100.

The simple layered structure illustrated in FIGS. 1 and 2 is provided byway of non-limiting example, and it is understood that embodiments ofthe invention may be used in connection with a wide variety of otherstructures. The specific materials and structures described areexemplary in nature, and other materials and structures may be used.Functional OLEDs may be achieved by combining the various layersdescribed in different ways, or layers may be omitted entirely, based ondesign, performance, and cost factors. Other layers not specificallydescribed may also be included. Materials other than those specificallydescribed may be used. Although many of the examples provided hereindescribe various layers as comprising a single material, it isunderstood that combinations of materials, such as a mixture of host anddopant, or more generally a mixture, may be used. Also, the layers mayhave various sublayers. The names given to the various layers herein arenot intended to be strictly limiting. For example, in device 200, holetransport layer 225 transports holes and injects holes into emissivelayer 220, and may be described as a hole transport layer or a holeinjection layer. In one embodiment, an OLED may be described as havingan “organic layer” disposed between a cathode and an anode. This organiclayer may comprise a single layer, or may further comprise multiplelayers of different organic materials as described, for example, withrespect to FIGS. 1 and 2.

Structures and materials not specifically described may also be used,such as OLEDs comprised of polymeric materials (PLEDs) such as disclosedin U.S. Pat. No. 5,247,190 to Friend et al., which is incorporated byreference in its entirety. By way of further example, OLEDs having asingle organic layer may be used. OLEDs may be stacked, for example asdescribed in U.S. Pat. No. 5,707,745 to Forrest et al, which isincorporated by reference in its entirety. The OLED structure maydeviate from the simple layered structure illustrated in FIGS. 1 and 2.For example, the substrate may include an angled reflective surface toimprove out-coupling, such as a mesa structure as described in U.S. Pat.No. 6,091,195 to Forrest et al., and/or a pit structure as described inU.S. Pat. No. 5,834,893 to Bulovic et al., which are incorporated byreference in their entireties.

Unless otherwise specified, any of the layers of the various embodimentsmay be deposited by any suitable method. For the organic layers,preferred methods include thermal evaporation, ink-jet, such asdescribed in U.S. Pat. Nos. 6,013,982 and 6,087,196, which areincorporated by reference in their entireties, organic vapor phasedeposition (OVPD), such as described in U.S. Pat. No. 6,337,102 toForrest et al., which is incorporated by reference in its entirety, anddeposition by organic vapor jet printing (OVJP), such as described inU.S. Pat. No. 7,431,968, which is incorporated by reference in itsentirety. Other suitable deposition methods include spin coating andother solution based processes. Solution based processes are preferablycarried out in nitrogen or an inert atmosphere. For the other layers,preferred methods include thermal evaporation. Preferred patterningmethods include deposition through a mask, cold welding such asdescribed in U.S. Pat. Nos. 6,294,398 and 6,468,819, which areincorporated by reference in their entireties, and patterning associatedwith some of the deposition methods such as ink-jet and OVJD. Othermethods may also be used. The materials to be deposited may be modifiedto make them compatible with a particular deposition method. Forexample, substituents such as alkyl and aryl groups, branched orunbranched, and preferably containing at least 3 carbons, may be used insmall molecules to enhance their ability to undergo solution processing.Substituents having 20 carbons or more may be used, and 3-20 carbons isa preferred range. Materials with asymmetric structures may have bettersolution processibility than those having symmetric structures, becauseasymmetric materials may have a lower tendency to recrystallize.Dendrimer substituents may be used to enhance the ability of smallmolecules to undergo solution processing.

Devices fabricated in accordance with embodiments of the presentinvention may further optionally comprise a barrier layer. One purposeof the barrier layer is to protect the electrodes and organic layersfrom damaging exposure to harmful species in the environment includingmoisture, vapor and/or gases, etc. The barrier layer may be depositedover, under or next to a substrate, an electrode, or over any otherparts of a device including an edge. The barrier layer may comprise asingle layer, or multiple layers. The barrier layer may be formed byvarious known chemical vapor deposition techniques and may includecompositions having a single phase as well as compositions havingmultiple phases. Any suitable material or combination of materials maybe used for the barrier layer. The barrier layer may incorporate aninorganic or an organic compound or both. The preferred barrier layercomprises a mixture of a polymeric material and a non-polymeric materialas described in U.S. Pat. No. 7,968,146, PCT Pat. Application Nos.PCT/US2007/023098 and PCT/US2009/042829, which are herein incorporatedby reference in their entireties. To be considered a “mixture”, theaforesaid polymeric and non-polymeric materials comprising the barrierlayer should be deposited under the same reaction conditions and/or atthe same time. The weight ratio of polymeric to non-polymeric materialmay be in the range of 95:5 to 5:95. The polymeric material and thenon-polymeric material may be created from the same precursor material.In one example, the mixture of a polymeric material and a non-polymericmaterial consists essentially of polymeric silicon and inorganicsilicon.

Devices fabricated in accordance with embodiments of the invention canbe incorporated into a wide variety of electronic component modules (orunits) that can be incorporated into a variety of electronic products orintermediate components. Examples of such electronic products orintermediate components include display screens, lighting devices suchas discrete light source devices or lighting panels, etc. that can beutilized by the end-user product manufacturers. Such electroniccomponent modules can optionally include the driving electronics and/orpower source(s). Devices fabricated in accordance with embodiments ofthe invention can be incorporated into a wide variety of consumerproducts that have one or more of the electronic component modules (orunits) incorporated therein. Such consumer products would include anykind of products that include one or more light source(s) and/or one ormore of some type of visual displays. Some examples of such consumerproducts include flat panel displays, computer monitors, medicalmonitors, televisions, billboards, lights for interior or exteriorillumination and/or signaling, heads-up displays, fully or partiallytransparent displays, flexible displays, laser printers, telephones,cell phones, tablets, phablets, personal digital assistants (PDAs),laptop computers, digital cameras, camcorders, viewfinders,micro-displays, 3-D displays, vehicles, a large area wall, theater orstadium screen, or a sign. Various control mechanisms may be used tocontrol devices fabricated in accordance with the present invention,including passive matrix and active matrix. Many of the devices areintended for use in a temperature range comfortable to humans, such as18 degrees C. to 30 degrees C., and more preferably at room temperature(20-25 degrees C.), but could be used outside this temperature range,for example, from −40 degree C. to +80 degree C.

The materials and structures described herein may have applications indevices other than OLEDs. For example, other optoelectronic devices suchas organic solar cells and organic photodetectors may employ thematerials and structures. More generally, organic devices, such asorganic transistors, may employ the materials and structures.

The term “halo,” “halogen,” or “halide” as used herein includesfluorine, chlorine, bromine, and iodine.

The term “alkyl” as used herein contemplates both straight and branchedchain alkyl radicals. Preferred alkyl groups are those containing fromone to fifteen carbon atoms and includes methyl, ethyl, propyl,isopropyl, butyl, isobutyl, tert-butyl, and the like. Additionally, thealkyl group may be optionally substituted.

The term “cycloalkyl” as used herein contemplates cyclic alkyl radicals.Preferred cycloalkyl groups are those containing 3 to 7 carbon atoms andincludes cyclopropyl, cyclopentyl, cyclohexyl, and the like.Additionally, the cycloalkyl group may be optionally substituted.

The term “alkenyl” as used herein contemplates both straight andbranched chain alkene radicals. Preferred alkenyl groups are thosecontaining two to fifteen carbon atoms. Additionally, the alkenyl groupmay be optionally substituted.

The term “alkynyl” as used herein contemplates both straight andbranched chain alkyne radicals. Preferred alkynyl groups are thosecontaining two to fifteen carbon atoms. Additionally, the alkynyl groupmay be optionally substituted.

The terms “aralkyl” or “arylalkyl” as used herein are usedinterchangeably and contemplate an alkyl group that has as a substituentan aromatic group. Additionally, the aralkyl group may be optionallysubstituted.

The term “heterocyclic group” as used herein contemplates aromatic andnon-aromatic cyclic radicals. Hetero-aromatic cyclic radicals also meansheteroaryl. Preferred hetero-non-aromatic cyclic groups are thosecontaining 3 or 7 ring atoms which includes at least one hetero atom,and includes cyclic amines such as morpholino, piperdino, pyrrolidino,and the like, and cyclic ethers, such as tetrahydropyran,tetrahydropyran, and the like. Additionally, the heterocyclic group maybe optionally substituted.

The term “aryl” or “aromatic group” as used herein contemplatessingle-ring groups and polycyclic ring systems. The polycyclic rings mayhave two or more rings in which two carbons are common to two adjoiningrings (the rings are “fused”) wherein at least one of the rings isaromatic, e.g., the other rings can be cycloalkyls, cycloalkenyls, aryl,heterocycles, and/or heteroaryls. Additionally, the aryl group may beoptionally substituted.

The term “heteroaryl” as used herein contemplates single-ringhetero-aromatic groups that may include from one to three heteroatoms,for example, pyrrole, furan, thiophene, imidazole, oxazole, thiazole,triazole, pyrazole, pyridine, pyrazine and pyrimidine, and the like. Theterm heteroaryl also includes polycyclic hetero-aromatic systems havingtwo or more rings in which two atoms are common to two adjoining rings(the rings are “fused”) wherein at least one of the rings is aheteroaryl, e.g., the other rings can be cycloalkyls, cycloalkenyls,aryl, heterocycles, and/or heteroaryls. Additionally, the heteroarylgroup may be optionally substituted.

The alkyl, cycloalkyl, alkenyl, alkynyl, aralkyl, heterocyclic group,aryl, and heteroaryl may be optionally substituted with one or moresubstituents selected from the group consisting of hydrogen, deuterium,halogen, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy, aryloxy,amino, cyclic amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl,alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylic acid, ether,ester, nitrile, isonitrile, sulfanyl, sulfanyl, sulfonyl, phosphino, andcombinations thereof.

As used herein, “substituted” indicates that a substituent other than His bonded to the relevant position, such as carbon. Thus, for example,where R¹ is mono-substituted, then one R¹ must be other than H.Similarly, where R¹ is di-substituted, then two of R¹ must be other thanH. Similarly, where R¹ is unsubstituted, R¹ is hydrogen for allavailable positions.

The “aza” designation in the fragments described herein, i.e.aza-dibenzofuran, aza-dibenzothiophene, etc. means that one or more ofthe C—H groups in the respective fragment can be replaced by a nitrogenatom, for example, and without any limitation, azatriphenyleneencompasses both dibenzo[f,h]quinoxaline and dibenzo[f,h]quinoline. Oneof ordinary skill in the art can readily envision other nitrogen analogsof the aza-derivatives described above, and all such analogs areintended to be encompassed by the terms as set forth herein.

It is to be understood that when a molecular fragment is described asbeing a substituent or otherwise attached to another moiety, its namemay be written as if it were a fragment (e.g. phenyl, phenylene,naphthyl, dibenzofuryl) or as if it were the whole molecule (e.g.benzene, naphthalene, dibenzofuran). As used herein, these differentways of designating a substituent or attached fragment are considered tobe equivalent.

The present disclosure provides a novel phosphorescent compound havingthe formula Ir(L_(A))_(n)(L_(B))_(3-n), and having a structure ofFormula I shown below:

In Formula I, R_(a), R_(b), and R_(c) each independently representmono-, di-, tri-, tetra-substitution, or no substitution;

wherein X is O, S, or Se; wherein n is an integer from 1 to 3;

wherein R_(a), R_(b), and R_(c) are each independently selected from thegroup consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl,heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl,cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl,carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl,sulfonyl, phosphino, and combinations thereof;

wherein R¹, R², R³, and R⁴ are each independently selected from thegroup consisting of hydrogen, deuterium, aryl, alkyl, cycloalkyl, andcombinations thereof;

wherein at least two of R¹, R², R³, and R⁴ are alkyl, cycloalkyl, orcombinations thereof; and

wherein any adjacent substitutions in R¹ to R⁴ and R_(a) to R_(c) areoptionally linked together to form a ring.

In some embodiments of the compound, at least two of R¹, R², R³, and R⁴are each independently selected from the group consisting of methyl,ethyl, n-propyl, 1-methylethyl, n-butyl, 1-methylpropyl, 2-methylpropyl,t-butyl, n-pentyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl,1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, cyclopentyl,cyclohexyl, and combinations thereof, wherein each group is optionallypartially or fully deuterated.

In one embodiment of the compound having the structure of Formula I, nis 1.

In one embodiment of the compound having the structure of Formula I, Xis O.

In one embodiment of the compound having the structure of Formula I, R¹and R⁴ are each independently selected from the group consisting ofalkyl, cycloalkyl, and combinations thereof, wherein each group isoptionally partially or fully deuterated, and R² and R³ are hydrogen.

In another embodiment of the compound having the structure of Formula I,R¹ and R³ are each independently selected from the group consisting ofalkyl, cycloalkyl, and combinations thereof, wherein each group isoptionally partially or fully deuterated, and R² and R⁴ are hydrogen.

In one embodiment of the compound having the structure of Formula I, R³and R⁴ are each independently selected from the group consisting ofalkyl, cycloalkyl, and combinations thereof, wherein each group isoptionally partially or fully deuterated, and R¹ and R² are hydrogen.

In one preferred embodiment of the compound having the structure ofFormula I, R¹, R³, and R⁴ are each independently selected from the groupconsisting of alkyl, cycloalkyl, and combinations thereof, wherein eachgroup is optionally partially or fully deuterated and R² is hydrogen.

In one embodiment of the compound having the structure of Formula I, anytwo of R¹, R², R³, and R⁴ are hydrogen.

In another embodiment of the compound having the structure of Formula I,R¹ is selected from the group consisting of alkyl, cycloalkyl, andcombinations thereof, wherein each group is optionally partially orfully deuterated.

In one embodiment of the compound, the total number of carbon atoms inR¹, R², R³, and R⁴ combined is at least 3. In another embodiment of thecompound, the total number of carbon atoms in R¹, R², R³, and R⁴ is atleast 4.

In one embodiment of the compound, R_(a), R_(b), and R_(c) are eachindependently selected from the group consisting of hydrogen, deuterium,alkyl, cycloalkyl, aryl, heteroaryl, and combinations thereof.

In one embodiment of the compound, L_(A) has a structure according tothe following formula:

and is selected from the group consisting of L_(A1) through L_(A438)wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷, and R⁸ are as defined in Tables 1Aand 1B provided below:

TABLE 1A Ligand L_(A) R¹ R² R³ R⁴ R⁵ R⁶ R⁷ R⁸ L_(A1) CH₃ CH₃ H H H H H HL_(A2) CH₃ H CH₃ H H H H H L_(A3) CH₃ H H CH₃ H H H H L_(A4) H CH₃ CH₃ HH H H H L_(A5) H CH₃ H CH₃ H H H H L_(A6) H H CH₃ CH₃ H H H H L_(A7) CD₃CD₃ H H H H H H L_(A8) CD₃ H CD₃ H H H H H L_(A9) CD₃ H H CD₃ H H H HL_(A10) H CD₃ CD₃ H H H H H L_(A11) H CD₃ H CD₃ H H H H L_(A12) H H CD₃CD₃ H H H H L_(A13) CH₃ CH₃ H H CH₃ H H H L_(A14) CH₃ H CH₃ H CH₃ H H HL_(A15) CH₃ H H CH₃ CH₃ H H H L_(A16) H CH₃ CH₃ H CH₃ H H H L_(A17) HCH₃ H CH₃ CH₃ H H H L_(A18) H H CH₃ CH₃ CH₃ H H H L_(A19) CD₃ CD₃ H HCD₃ H H H L_(A20) CD₃ H CD₃ H CD₃ H H H L_(A21) CD₃ H H CD₃ CD₃ H H HL_(A22) H CD₃ CD₃ H CD₃ H H H L_(A23) H CD₃ H CD₃ CD₃ H H H L_(A24) H HCD₃ CD₃ CD₃ H H H L_(A25) CH₃ CH₃ H H H CH₃ H H L_(A26) CH₃ H CH₃ H HCH₃ H H L_(A27) CH₃ H H CH₃ H CH₃ H H L_(A28) H CH₃ CH₃ H H CH₃ H HL_(A29) H CH₃ H CH₃ H CH₃ H H L_(A30) H H CH₃ CH₃ H CH₃ H H L_(A31) CD₃CD₃ H H H CD₃ H H L_(A32) CD₃ H CD₃ H H CD₃ H H L_(A33) CD₃ H H CD₃ HCD₃ H H L_(A34) H CD₃ CD₃ H H CD₃ H H L_(A35) H CD₃ H CD₃ H CD₃ H HL_(A36) H H CD₃ CD₃ H CD₃ H H L_(A37) CH₃ CH₃ H H H H CH₃ H L_(A38) CH₃H CH₃ H H H CH₃ H L_(A39) CH₃ H H CH₃ H H CH₃ H L_(A40) H CH₃ CH₃ H H HCH₃ H L_(A41) H CH₃ H CH₃ H H CH₃ H L_(A42) H H CH₃ CH₃ H H CH₃ HL_(A43) CD₃ CD₃ H H H H CD₃ H L_(A44) CD₃ H CD₃ H H H CD₃ H L_(A45) CD₃H H CD₃ H H CD₃ H L_(A46) H CD₃ CD₃ H H H CD₃ H L_(A47) H CD₃ H CD₃ H HCD₃ H L_(A48) H H CD₃ CD₃ H H CD₃ H L_(A49) CH₃ CH₃ H H H H H CH₃L_(A50) CH₃ H CH₃ H H H H CH₃ L_(A51) CH₃ H H CH₃ H H H CH₃ L_(A52) HCH₃ CH₃ H H H H CH₃ L_(A53) H CH₃ H CH₃ H H H CH₃ L_(A54) H H CH₃ CH₃ HH H CH₃ L_(A55) CD₃ CD₃ H H H H H CD₃ L_(A56) CD₃ H CD₃ H H H H CD₃L_(A57) CD₃ H H CD₃ H H H CD₃ L_(A58) H CD₃ CD₃ H H H H CD₃ L_(A59) HCD₃ H CD₃ H H H CD₃ L_(A60) H H CD₃ CD₃ H H H CD₃ L_(A61) CH₃ CH₃ H HCH(CH₃)₂ H H H L_(A62) CH₃ H CH₃ H CH(CH₃)₂ H H H L_(A63) CH₃ H H CH₃CH(CH₃)₂ H H H L_(A64) H CH₃ CH₃ H CH(CH₃)₂ H H H L_(A65) H CH₃ H CH₃CH(CH₃)₂ H H H L_(A66) H H CH₃ CH₃ CH(CH₃)₂ H H H L_(A67) CD₃ CD₃ H HCD(CD₃)₂ H H H L_(A68) CD₃ H CD₃ H CD(CD₃)₂ H H H L_(A69) CD₃ H H CD₃CD(CD₃)₂ H H H L_(A70) H CD₃ CD₃ H CD(CD₃)₂ H H H L_(A71) H CD₃ H CD₃CD(CD₃)₂ H H H L_(A72) H H CD₃ CD₃ CD(CD₃)₂ H H H L_(A73) CH₃ CH₃ H H HCH(CH₃)₂ H H L_(A74) CH₃ H CH₃ H H CH(CH₃)₂ H H L_(A75) CH₃ H H CH₃ HCH(CH₃)₂ H H L_(A76) H CH₃ CH₃ H H CH(CH₃)₂ H H L_(A77) H CH₃ H CH₃ HCH(CH₃)₂ H H L_(A78) H H CH₃ CH₃ H CH(CH₃)₂ H H L_(A79) CD₃ CD₃ H H HCD(CD₃)₂ H H L_(A80) CD₃ H CD₃ H H CD(CD₃)₂ H H L_(A81) CD₃ H H CD₃ HCD(CD₃)₂ H H L_(A82) H CD₃ CD₃ H H CD(CD₃)₂ H H L_(A83) H CD₃ H CD₃ HCD(CD₃)₂ H H L_(A84) H H CD₃ CD₃ H CD(CD₃)₂ H H L_(A85) CH₃ CH₃ H H H HCH(CH₃)₂ H L_(A86) CH₃ H CH₃ H H H CH(CH₃)₂ H L_(A87) CH₃ H H CH₃ H HCH(CH₃)₂ H L_(A88) H CH₃ CH₃ H H H CH(CH₃)₂ H L_(A89) H CH₃ H CH₃ H HCH(CH₃)₂ H L_(A90) H H CH₃ CH₃ H H CH(CH₃)₂ H L_(A91) CD₃ CD₃ H H H HCD(CD₃)₂ H L_(A92) CD₃ H CD₃ H H H CD(CD₃)₂ H L_(A93) CD₃ H H CD₃ H HCD(CD₃)₂ H L_(A94) H CD₃ CD₃ H H H CD(CD₃)₂ H L_(A95) H CD₃ H CD₃ H HCD(CD₃)₂ H L_(A96) H H CD₃ CD₃ H H CD(CD₃)₂ H L_(A97) CD₃ H CD₃ H H HCD(CH₃)₂ H L_(A98) CH₂CH₃ CH₃ H H H CH(CH₃)₂ H H L_(A99) CH₂CH₃ H CH₃ HH CH(CH₃)₂ H H L_(A100) CH₂CH₃ H H CH₃ H CH(CH₃)₂ H H L_(A101) H CH₂CH₃CH₃ H H CH(CH₃)₂ H H L_(A102) H CH₂CH₃ H CH₃ H CH(CH₃)₂ H H L_(A103) H HCH₂CH₃ CH₃ H CH(CH₃)₂ H H L_(A104) H H CH₃ CH₂CH₃ H CH(CH₃)₂ H HL_(A105) H CH₃ H CH₂CH₃ H CH(CH₃)₂ H H L_(A106) CH₃ H H CH₂CH₃ HCH(CH₃)₂ H H L_(A107) CD₂CD₃ CD₃ H H H CD(CD₃)₂ H H L_(A108) CD₂CD₃ HCD₃ H H CD(CD₃)₂ H H L_(A109) CD₂CD₃ H H CD₃ H CD(CD₃)₂ H H L_(A110)CD₂CD₃ H H CD₃ H CD(CH₃)₂ H H L_(A111) CH₂CH₃ CH₃ H H H H CH(CH₃)₂ HL_(A112) CH₂CH₃ H CH₃ H H H CH(CH₃)₂ H L_(A113) CH₂CH₃ H H CH₃ H HCH(CH₃)₂ H L_(A114) H CH₂CH₃ CH₃ H H H CH(CH₃)₂ H L_(A115) H CH₂CH₃ HCH₃ H H CH(CH₃)₂ H L_(A116) H H CH₂CH₃ CH₃ H H CH(CH₃)₂ H L_(A117) H HCH₃ CH₂CH₃ H H CH(CH₃)₂ H L_(A118) H CH₃ H CH₂CH₃ H H CH(CH₃)₂ HL_(A119) CH₃ H H CH₂CH₃ H H CH(CH₃)₂ H L_(A120) CD₂CD₃ CD₃ H H H HCD(CD₃)₂ H L_(A121) CD₂CD₃ H CD₃ H H H CD(CD₃)₂ H L_(A122) CD₂CD₃ H HCD₃ H H CD(CD₃)₂ H L_(A123) CD₃ H H CD₂CH₃ H H CD(CH₃)₂ H L_(A124) CD₃ HH CD₂CH₃ H H H CD₃ L_(A125) CH₃ CH₃ H H H H H CH(CH₃)₂ L_(A126) CH₃ HCH₃ H H H H CH(CH₃)₂ L_(A127) CH₃ H H CH₃ H H H CH(CH₃)₂ L_(A128) H CH₃CH₃ H H H H CH(CH₃)₂ L_(A129) H CH₃ H CH₃ H H H CH(CH₃)₂ L_(A130) H HCH₃ CH₃ H H H CH(CH₃)₂ L_(A131) CD₃ CD₃ H H H H H CD(CD₃)₂ L_(A132) CD₃H CD₃ H H H H CD(CD₃)₂ L_(A133) CD₃ H H CD₃ H H H CD(CD₃)₂ L_(A134) HCD₃ CD₃ H H H H CD(CD₃)₂ L_(A135) H CD₃ H CD₃ H H H CD(CD₃)₂ L_(A136) HH CD₃ CD₃ H H H CD(CD₃)₂ L_(A137) CH₃ CH₃ H H H CH₂CH(CH₃)₂ H H L_(A138)CH₃ H CH₃ H H CH₂CH(CH₃)₂ H H L_(A139) CH₃ H H CH₃ H CH₂CH(CH₃)₂ H HL_(A140) H CH₃ CH₃ H H CH₂CH(CH₃)₂ H H L_(A141) H CH₃ H CH₃ HCH₂CH(CH₃)₂ H H L_(A142) H H CH₃ CH₃ H CH₂CH(CH₃)₂ H H L_(A143) CD₃ CD₃H H H CD₂CH(CH₃)₂ H H L_(A144) CD₃ H CD₃ H H CD₂CH(CH₃)₂ H H L_(A145)CD₃ H H CD₃ H CD₂CH(CH₃)₂ H H L_(A146) H CD₃ CD₃ H H CD₂CH(CH₃)₂ H HL_(A147) H CD₃ H CD₃ H CD₂CH(CH₃)₂ H H L_(A148) H H CD₃ CD₃ HCD₂CH(CH₃)₂ H H L_(A149) CH₃ CH₃ H H H H CH₂CH(CH₃)₂ H L_(A150) CH₃ HCH₃ H H H CH₂CH(CH₃)₂ H L_(A151) CH₃ H H CH₃ H H CH₂CH(CH₃)₂ H L_(A152)H CH₃ CH₃ H H H CH₂CH(CH₃)₂ H L_(A153) H CH₃ H CH₃ H H CH₂CH(CH₃)₂ HL_(A154) H H CH₃ CH₃ H H CH₂CH(CH₃)₂ H L_(A155) CD₃ CD₃ H H H HCD₂CH(CH₃)₂ H L_(A156) CD₃ H CD₃ H H H CD₂CH(CH₃)₂ H L_(A157) CD₃ H HCD₃ H H CD₂CH(CH₃)₂ H L_(A158) H CD₃ CD₃ H H H CD₂CH(CH₃)₂ H L_(A159) HCD₃ H CD₃ H H CD₂CH(CH₃)₂ H L_(A160) H H CD₃ CD₃ H H CD₂CH(CH₃)₂ HL_(A161) CH₃ CH₃ H H CH₃ CH₃ H H L_(A162) CH₃ H CH₃ H CH₃ CH₃ H HL_(A163) CH₃ H H CH₃ CH₃ CH₃ H H L_(A164) H CH₃ CH₃ H CH₃ CH₃ H HL_(A165) H CH₃ H CH₃ CH₃ CH₃ H H L_(A166) H H CH₃ CH₃ CH₃ CH₃ H HL_(A167) CD₃ CD₃ H H CD₃ CD₃ H H L_(A168) CD₃ H CD₃ H CD₃ CD₃ H HL_(A169) CD₃ H H CD₃ CD₃ CD₃ H H L_(A170) H CD₃ CD₃ H CD₃ CD₃ H HL_(A171) H CD₃ H CD₃ CD₃ CD₃ H H L_(A172) H H CD₃ CD₃ CD₃ CD₃ H HL_(A173) CH₃ CH₃ H H H CH₃ CH₃ H L_(A174) CH₃ H CH₃ H H CH₃ CH₃ HL_(A175) CH₃ H H CH₃ H CH₃ CH₃ H L_(A176) H CH₃ CH₃ H H CH₃ CH₃ HL_(A177) H CH₃ H CH₃ H CH₃ CH₃ H L_(A178) H H CH₃ CH₃ H CH₃ CH₃ HL_(A179) CD₃ CD₃ H H H CD₃ CD₃ H L_(A180) CD₃ H CD₃ H H CD₃ CD₃ HL_(A181) CD₃ H H CD₃ H CD₃ CD₃ H L_(A182) H CD₃ CD₃ H H CD₃ CD₃ HL_(A183) H CD₃ H CD₃ H CD₃ CD₃ H L_(A184) H H CD₃ CD₃ H CD₃ CD₃ HL_(A185) CH₃ CH₃ H H H CH(CH₃)₂ CH₃ H L_(A186) CH₃ H CH₃ H H CH(CH₃)₂CH₃ H L_(A187) CH₃ H H CH₃ H CH(CH₃)₂ CH₃ H L_(A188) H CH₃ CH₃ H HCH(CH₃)₂ CH₃ H L_(A189) H CH₃ H CH₃ H CH(CH₃)₂ CH₃ H L_(A190) H H CH₃CH₃ H CH(CH₃)₂ CH₃ H L_(A191) CD₃ CD₃ H H H CD(CD₃)₂ CD₃ H L_(A192) CD₃H CD₃ H H CD(CD₃)₂ CD₃ H L_(A193) CD₃ H H CD₃ H CD(CD₃)₂ CD₃ H L_(A194)H CD₃ CD₃ H H CD(CD₃)₂ CD₃ H L_(A195) H CD₃ H CD₃ H CD(CD₃)₂ CD₃ HL_(A196) H H CD₃ CD₃ H CD(CD₃)₂ CD₃ H L_(A197) CH₃ CH₃ H H H CH₃CH(CH₃)₂ H L_(A198) CH₃ H CH₃ H H CH₃ CH(CH₃)₂ H L_(A199) CH₃ H H CH₃ HCH₃ CH(CH₃)₂ H L_(A200) H CH₃ CH₃ H H CH₃ CH(CH₃)₂ H L_(A201) H CH₃ HCH₃ H CH₃ CH(CH₃)₂ H L_(A202) H H CH₃ CH₃ H CH₃ CH(CH₃)₂ H L_(A203) CD₃CD₃ H H H CD₃ CD(CD₃)₂ H L_(A204) CD₃ H CD₃ H H CD₃ CD(CD₃)₂ H L_(A205)CD₃ H H CD₃ H CD₃ CD(CD₃)₂ H L_(A206) H CD₃ CD₃ H H CD₃ CD(CD₃)₂ HL_(A207) H CD₃ H CD₃ H CD₃ CD(CD₃)₂ H L_(A208) H H CD₃ CD₃ H CD₃CD(CD₃)₂ H L_(A209) CH₃ CH₃ H H H CH₂CH(CH₃)₂ CH₃ H L_(A210) CH₃ H CH₃ HH CH₂CH(CH₃)₂ CH₃ H L_(A211) CH₃ H H CH₃ H CH₂CH(CH₃)₂ CH₃ H L_(A212) HCH₃ CH₃ H H CH₂CH(CH₃)₂ CH₃ H L_(A213) H CH₃ H CH₃ H CH₂CH(CH₃)₂ CH₃ HL_(A214) H H CH₃ CH₃ H CH₂CH(CH₃)₂ CH₃ H L_(A215) CD₃ CD₃ H H HCD₂CH(CH₃)₂ CD₃ H L_(A216) CD₃ H CD₃ H H CD₂CH(CH₃)₂ CD₃ H L_(A217) CD₃H H CD₃ H CD₂CH(CH₃)₂ CD₃ H L_(A218) H CD₃ CD₃ H H CD₂CH(CH₃)₂ CD₃ HL_(A219) H CD₃ H CD₃ H CD₂CH(CH₃)₂ CD₃ H L_(A220) H H CD₃ CD₃ HCD₂CH(CH₃)₂ CD₃ H L_(A221) CH₃ CH₃ H H H CH₃ CH₂CH(CH₃)₂ H L_(A222) CH₃H CH₃ H H CH₃ CH₂CH(CH₃)₂ H L_(A223) CH₃ H H CH₃ H CH₃ CH₂CH(CH₃)₂ HL_(A224) H CH₃ CH₃ H H CH₃ CH₂CH(CH₃)₂ H L_(A225) H CH₃ H CH₃ H CH₃CH₂CH(CH₃)₂ H L_(A226) H H CH₃ CH₃ H CH₃ CH₂CH(CH₃)₂ H L_(A227) CD₃ CD₃H H H CD₃ CD₂CH(CH₃)₂ H L_(A228) CD₃ H CD₃ H H CD₃ CD₂CH(CH₃)₂ HL_(A229) CD₃ H H CD₃ H CD₃ CD₂CH(CH₃)₂ H L_(A230) H CD₃ CD₃ H H CD₃CD₂CH(CH₃)₂ H L_(A231) H CD₃ H CD₃ H CD₃ CD₂CH(CH₃)₂ H L_(A232) H H CD₃CD₃ H CD₃ CD₂CH(CH₃)₂ H L_(A233) CH(CH₃)₂ CH₃ H H H H H H L_(A234) CH₃CH(CH₃)₂ H H H H H H L_(A235) CH(CH₃)₂ H CH₃ H H H H H L_(A236) CH₃ HCH(CH₃)₂ H H H H H L_(A237) CH(CH₃)₂ H H CH₃ H H H H L_(A238) CH₃ H HCH(CH₃)₂ H H H H L_(A239) H CH(CH₃)₂ CH₃ H H H H H L_(A240) H CH(CH₃)₂ HCH₃ H H H H L_(A241) H H CH(CH₃)₂ CH₃ H H H H L_(A242) CH(CH₃)₂ H HCH(CH₃)₂ H H H H L_(A243) CD(CH₃)₂ CD3 H H H H H H L_(A244) CD(CH₃)₂ HCD₃ H H H H H L_(A245) CD(CH₃)₂ H H CD₃ H H H H L_(A246) H CD(CH₃)₂ CD₃H H H H H L_(A247) H CD(CH₃)₂ H CD₃ H H H H L_(A248) CD₃ H H CD(CH₃)₂ HH H H L_(A249) CD(CH₃)₂ H CD(CH₃)₂ H H H H H L_(A250) CD(CH₃)₂ H HCD(CH₃)₂ H H H H L_(A251) CH(CH₃)₂ CH₃ H H H CH(CH₃)₂ H H L_(A252) CH₃CH(CH₃)₂ H H H CH(CH₃)₂ H H L_(A253) CH(CH₃)₂ H CH₃ H H CH(CH₃)₂ H HL_(A254) CH₃ H CH(CH₃)₂ H H CH(CH₃)₂ H H L_(A255) CH(CH₃)₂ H H CH₃ HCH(CH₃)₂ H H L_(A256) CH₃ H H CH(CH₃)₂ H CH(CH₃)₂ H H L_(A257) HCH(CH₃)₂ CH₃ H H CH(CH₃)₂ H H L_(A258) H CH(CH₃)₂ H CH₃ H CH(CH₃)₂ H HL_(A259) H H CH(CH₃)₂ CH₃ H CH(CH₃)₂ H H L_(A260) CH(CH₃)₂ H H CH(CH₃)₂H CH(CH₃)₂ H H L_(A261) CD(CH₃)₂ CD₃ H H H CD(CD₃)₂ H H L_(A262)CD(CH₃)₂ H CD₃ H H CD(CD₃)₂ H H L_(A263) CD(CH₃)₂ H H CD₃ H CD(CD₃)₂ H HL_(A264) H CD(CH₃)₂ CD₃ H H CD(CD₃)₂ H H L_(A265) H CD(CH₃)₂ H CD₃ HCD(CD₃)₂ H H L_(A266) CD₃ H H CD(CH₃)₂ H CD(CD₃)₂ H H L_(A267) CD(CH₃)₂H CD(CH₃)₂ H H CD(CD₃)₂ H H L_(A268) CD(CH₃)₂ H H CD(CH₃)₂ H CD(CD₃)₂ HH L_(A269) CH(CH₃)₂ CH₃ H H H CH₃ CH(CH₃)₂ H L_(A270) CH₃ CH(CH₃)₂ H H HCH₃ CH(CH₃)₂ H L_(A271) CH(CH₃)₂ H CH₃ H H CH₃ CH(CH₃)₂ H L_(A272) CH₃ HCH(CH₃)₂ H H CH₃ CH(CH₃)₂ H L_(A273) CH(CH₃)₂ H H CH₃ H CH₃ CH(CH₃)₂ HL_(A274) CH₃ H H CH(CH₃)₂ H CH₃ CH(CH₃)₂ H L_(A275) H CH(CH₃)₂ CH₃ H HCH₃ CH(CH₃)₂ H L_(A276) H CH(CH₃)₂ H CH₃ H CH₃ CH(CH₃)₂ H L_(A277) H HCH(CH₃)₂ CH₃ H CH₃ CH(CH₃)₂ H L_(A278) CH(CH₃)₂ H H CH(CH₃)₂ H CH₃CH(CH₃)₂ H L_(A279) CD(CH₃)₂ CD₃ H H H CD₃ CH(CH₃)₂ H L_(A280) CD(CH₃)₂H CD₃ H H CD₃ CH(CH₃)₂ H L_(A281) CD(CH₃)₂ H H CD₃ H CD₃ CH(CH₃)₂ HL_(A282) H CD(CH₃)₂ CD₃ H H CD₃ CH(CH₃)₂ H L_(A283) H CD(CH₃)₂ H CD₃ HCD₃ CH(CH₃)₂ H L_(A284) CD₃ H H CD(CH₃)₂ H CD₃ CH(CH₃)₂ H L_(A285)CD(CH₃)₂ H CD(CH₃)₂ H H CD₃ CH(CH₃)₂ H L_(A286) CD(CH₃)₂ H H CD(CH₃)₂ HCD₃ CH(CH₃)₂ H L_(A287) CH(CH₃)₂ CH₃ H H H CH(CH₃)₂ CH₃ H L_(A288) CH₃CH(CH₃)₂ H H H CH(CH₃)₂ CH₃ H L_(A289) CH(CH₃)₂ H CH₃ H H CH(CH₃)₂ CH₃ HL_(A290) CH₃ H CH(CH₃)₂ H H CH(CH₃)₂ CH₃ H L_(A291) CH(CH₃)₂ H H CH₃ HCH(CH₃)₂ CH₃ H L_(A292) CH₃ H H CH(CH₃)₂ H CH(CH₃)₂ CH₃ H L_(A293) HCH(CH₃)₂ CH₃ H H CH(CH₃)₂ CH₃ H L_(A294) H CH(CH₃)₂ H CH₃ H CH(CH₃)₂ CH₃H L_(A295) H H CH(CH₃)₂ CH₃ H CH(CH₃)₂ CH₃ H L_(A296) CH(CH₃)₂ H HCH(CH₃)₂ H CD(CH₃)₂ CH₃ H L_(A297) CD(CH₃)₂ CD₃ H H H CD(CH₃)₂ CD₃ HL_(A298) CD(CH₃)₂ H CD₃ H H CD(CH₃)₂ CD₃ H L_(A299) CD(CH₃)₂ H H CD₃ HCD(CH₃)₂ CD₃ H L_(A300) H CD(CH₃)₂ CD₃ H H CD(CH₃)₂ CD₃ H L_(A301) HCD(CH₃)₂ H CD₃ H CD(CH₃)₂ CD₃ H L_(A302) CD₃ H H CD(CH₃)₂ H CD(CH₃)₂ CD₃H L_(A303) CD(CH₃)₂ H CD(CH₃)₂ H H CD(CH₃)₂ CD₃ H L_(A304) CD(CH₃)₂ H HCD(CH₃)₂ H CD(CH₃)₂ CD₃ H L_(A305) CD(CH₃)₂ H H CD(CH₃)₂ H CD(CD₃)₂ CD₃H L_(A306) CD₃ CD₃ H H H CD(CH₃)₂ H H L_(A307) CD₃ H CD₃ H H CD(CH₃)₂ HH L_(A308) CD₃ H H CD₃ H CD(CH₃)₂ H H L_(A309) H CD₃ CD₃ H H CD(CH₃)₂ HH L_(A310) H CD₃ H CD₃ H CD(CH₃)₂ H H L_(A311) H H CD₃ CD₃ H CD(CH₃)₂ HH L_(A312) CH₃ CH₃ CH₃ CH₃ H H H H L_(A313) CH₃ CH₃ CH₃ H H H H HL_(A314) CH₃ H CH₃ CH₃ H H H H L_(A315) H CH₃ CH₃ CH₃ H H H H L_(A316)CD₃ CD₃ CD₃ H H H H H L_(A317) CD₃ H CD₃ CD₃ H H H H L_(A318) CD₃ CD₃ HCD₃ H H H H L_(A319) H CD₃ CD₃ CD₃ H H H H L_(A320) CD₃ CD₃ CD₃ CD₃ H HH H L_(A321) CD₃ H CD₃ CD₃ H CD(CD₃)₂ H H L_(A322) CD₃ H CD₃ CD₃ H HCD(CD₃)₂ H L_(A323) CD₃ H CD₃ CD₃ H CD(CD₃)₂ CD₃ H L_(A324) CD₃ H CD₃CD₃ H CD₃ CD(CD₃)₂ H L_(A325) CD₃ H CD₃ CD(CH₃)₂ H H H H L_(A326) CD₃ HCD₃ CD(CH₃)₂ H CD(CD₃)₂ H H L_(A327) CD₃ H CD₃ CD(CH₃)₂ H H CD(CD₃)₂ HL_(A328) CD₃ H CD₃ CD(CH₃)₂ H CD(CD₃)₂ CD₃ H L_(A329) CD₃ H CD₃ CD(CH₃)₂H CD₃ CD(CD₃)₂ H L_(A330) CD₃ H CD(CH₃)₂ CD₃ H H H H L_(A331) CD₃ HCD(CH₃)₂ CD₃ H CD(CD₃)₂ H H L_(A332) CD₃ H CD(CH₃)₂ CD₃ H H CD(CD₃)₂ HL_(A333) CD₃ H CD(CH₃)₂ CD₃ H CD(CD₃)₂ CD₃ H L_(A334) CD₃ H CD(CH₃)₂ CD₃H CD₃ CD(CD₃)₂ H L_(A335) CD₃ H CD(CH₃)₂ CD(CH₃)₂ H H H H L_(A336) CD₃ HCD(CH₃)₂ CD(CH₃)₂ H CD(CD₃)₂ H H L_(A337) CD₃ H CD(CH₃)₂ CD(CH₃)₂ H HCD(CD₃)₂ H L_(A338) CD₃ H CD(CH₃)₂ CD(CH₃)₂ H CD(CD₃)₂ CD₃ H L_(A339)CD₃ H CD(CH₃)₂ CD(CH₃)₂ H CD₃ CD(CD₃)₂ H L_(A340) CD(CH₃)₂ H CD₃ H H HCD(CD₃)₂ H L_(A341) CD(CH₃)₂ H CD₃ H H CD₃ CD(CD₃)₂ H L_(A342) CD(CH₃)₂H CD₃ H H CD(CD₃)₂ CD₃ H L_(A343) CD(CH₃)₂ H CD₃ CD₃ H H H H L_(A344)CD(CH₃)₂ H CD₃ CD₃ H CD(CD₃)₂ H H L_(A345) CD(CH₃)₂ H CD₃ CD₃ H HCD(CD₃)₂ H L_(A346) CD(CH₃)₂ H CD₃ CD₃ H CD₃ CD(CD₃)₂ H L_(A347)CD(CH₃)₂ H CD₃ CD₃ H CD(CD₃)₂ CD₃ H L_(A348) CD₃ H H CD(CH₃)₂ H CD(CD₃)₂H H L_(A349) CD₃ H H CD(CH₃)₂ H H CD(CD₃)₂ H L_(A350) CD₃ H H CD(CH₃)₂ HCD(CD₃)₂ CD₃ H L_(A351) CD₃ H H CD(CH₃)₂ H CD₃ CD(CD₃)₂ H L_(A352) CD₃ HCD(CH₃)₂ H H H H H L_(A353) CD₃ H CD(CH₃)₂ H H CD(CD₃)₂ H H L_(A354) CD₃H CD(CH₃)₂ H H H CD(CD₃)₂ H L_(A355) CD₃ H CD(CH₃)₂ H H CD(CD₃)₂ CD₃ HL_(A356) CD₃ H CD(CH₃)₂ H H CD₃ CD(CD₃)₂ H

TABLE 1B Ligand L_(A) R¹ R² R³ R⁴ R⁵ R⁶ R⁷ R⁸ L_(A357)

CH₃ H H H H H H L_(A358)

H CH₃ H H H H H L_(A359)

H H CH₃ H H H H L_(A360) H

CH₃ H H H H H L_(A361) H

H CH₃ H H H H L_(A362) H H

CH₃ H H H H L_(A363) CH₃ H H

H H H H L_(A364) H CH₃ H

H H H H L_(A365) H H CH₃

H H H H L_(A366)

CD₃ H H H H H H L_(A367)

H CD₃ H H H H H L_(A368)

H H CD₃ H H H H L_(A369) H

CD₃ H H H H H L_(A370) H

H CD₃ H H H H L_(A371) H H

CD₃ H H H H L_(A372) CD₃ H H

H H H H L_(A373) H CD₃ H

H H H H L_(A374) H H CD₃

H H H H L_(A375)

CH₃ H H H H H H L_(A376)

H CH₃ H H H H H L_(A377)

H H CH₃ H H H H L_(A378) H

CH₃ H H H H H L_(A379) H

H CH₃ H H H H L_(A380) H H

CH₃ H H H H L_(A381) CH₃ H H

H H H H L_(A382) H CH₃ H

H H H H L_(A383) H H CH₃

H H H H L_(A384)

CD₃ H H H H H H L_(A385)

H CD₃ H H H H H L_(A386)

H H CD₃ H H H H L_(A387) H

CD₃ H H H H H L_(A388) H

H CD₃ H H H H L_(A389) H H

CD₃ H H H H L_(A390) CD₃ H H

H H H H L_(A391) H CD₃ H

H H H H L_(A392) H H CD₃

H H H H L_(A393)

H H CH₃ H H CH3 H L_(A394)

CH₃ H H H CH(CH₃)₂ H H L_(A395)

H CH₃ H H CH(CH₃)₂ H H L_(A396)

H H CH₃ H CH(CH₃)₂ H H L_(A397) H

CH₃ H H CH(CH₃)₂ H H L_(A398) H

H CH₃ H CH(CH₃)₂ H H L_(A399) H H

CH₃ H CH(CH₃)₂ H H L_(A400)

CD₃ H H H CD(CD₃)₂ H H L_(A401)

H CD₃ H H CD(CD₃)₂ H H L_(A402)

H H CD₃ H CD(CD₃)₂ H H L_(A403) H

CD₃ H H CD(CD₃)₂ H H L_(A404) H

H CD₃ H CD(CD₃)₂ H H L_(A405) H H

CD₃ H CD(CD₃)₂ H H L_(A406)

CD₃ H H H CD(CH₃)₂ H H L_(A407)

H CD₃ H H CD(CH₃)₂ H H L_(A408)

H H CD₃ H CD(CH₃)₂ H H L_(A409) H

CD₃ H H CD(CH₃)₂ H H L_(A410) H

H CD₃ H CD(CH₃)₂ H H L_(A411) H H

CD₃ H CD(CH₃)₂ H H L_(A412)

H CH₃ H H CD(CD₃)₂ H H L_(A413)

CH₃ H H H CH(CH₃)₂ H H L_(A414)

H CH₃ H H CH(CH₃)₂ H H L_(A415)

H H CH₃ H CH(CH₃)₂ H H L_(A416) H

CH₃ H H CH(CH₃)₂ H H L_(A417) H

H CH₃ H CH(CH₃)₂ H H L_(A418) H H

CH₃ H CH(CH₃)₂ H H L_(A4194)

CD₃ H H H CD(CD₃)₂ H H L_(A420)

H CD₃ H H CD(CD₃)₂ H H L_(A421)

H H CD₃ H CD(CD₃)₂ H H L_(A422) H

CD₃ H H CD(CD₃)₂ H H L_(A423) H

H CD₃ H CD(CD₃)₂ H H L_(A424) H H

CD₃ H CD(CD₃)₂ H H L_(A425)

CD₃ H H H CD(CH₃)₂ H H L_(A426)

H CD₃ H H CD(CH₃)₂ H H L_(A427)

H H CD₃ H CD(CH₃)₂ H H L_(A428) H

CD₃ H H CD(CH₃)₂ H H L_(A429) H

H CD₃ H CD(CH₃)₂ H H L_(A430) H H

CD₃ H CD(CH₃)₂ H H L_(A431) CD₃ H H

H CD(CH₃)₂ H H L_(A432) H H CD₃

H CD(CH₃)₂ H H L_(A433) H CD₃ H

H CD(CH₃)₂ H H L_(A434)

H H

H CD(CH₃)₂ H H L_(A435)

H H

H CD(CH₃)₂ H H L_(A436)

H H

H CD(CH₃)₂ H H L_(A437)

H H

H CD(CH₃)₂ H H L_(A438)

H H

H CD(CH₃)₂ H H

In another embodiment of the compound, L_(B) is selected from the groupconsisting of:

In one embodiment of the compound, the compound is selected from thegroup consisting of:

According to another aspect of the present disclosure, a devicecomprising one or more organic light emitting devices is disclosed. Atleast one of the one or more organic light emitting devices comprise: ananode; a cathode; and an organic layer disposed between the anode andthe cathode. The organic layer comprises a compound having the formulaIr(L_(A))_(n)(L_(B))_(3-n), and having the structure according toFormula I shown below:

In Formula I, R_(a), R_(b), and R_(c) each independently representmono-, di-, tri-, tetra-substitution, or no substitution;

wherein X is O, S, or Se;

wherein n is an integer from 1 to 3;

wherein R_(a), R_(b), and R_(c) are each independently selected from thegroup consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl,heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl,cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl,carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl,sulfonyl, phosphino, and combinations thereof;

wherein R¹, R², R³, and R⁴ are each independently selected from thegroup consisting of hydrogen, deuterium, aryl, alkyl, cycloalkyl, andcombinations thereof;

wherein at least two of R¹, R², R³, and R⁴ are alkyl, cycloalkyl, orcombinations thereof; and

wherein any adjacent substitutions in R¹ to R⁴ and R_(a) to R_(c) areoptionally linked together to form a ring.

In one embodiment of the device, the device is selected from the groupconsisting of a consumer product, an electronic component module, anorganic light-emitting device, and a lighting panel.

In some embodiments of the device, the organic layer is an emissivelayer and the compound is an emissive dopant or a non-emissive dopant.

The organic layer can further comprise a host; wherein the hostcomprises a triphenylene containing benzo-fused thiophene or benzo-fusedfuran; wherein any substituent in the host is an unfused substituentindependently selected from the group consisting of C_(n)H_(2n+1),OC_(n)H_(2n+1), OAr₁, N(C_(n)H_(2n+1))₂, N(Ar₁)(Ar₂),CH═CH—C_(n)H_(2n+1), C≡CC_(n)H_(2n+1), Ar₁, Ar₁-Ar₂, C_(n)H_(2n)—Ar₁, orno substitution; wherein n is from 1 to 10; and wherein Ar₁ and Ar₂ areindependently selected from the group consisting of benzene, biphenyl,naphthalene, triphenylene, carbazole, and heteroaromatic analogsthereof.

In one embodiment of the device, the organic layer further comprises ahost material, wherein the host comprises at least one chemical groupselected from the group consisting of triphenylene, carbazole,dibenzothiphene, dibenzofuran, dibenzoselenophene, azatriphenylene,azacarbazole, aza-dibenzothiophene, aza-dibenzofuran, andaza-dibenzoselenophene.

In another embodiment of the device, the host material can be a specificcompound selected from the group consisting of:

and combinations thereof.

In another embodiment of the device, the host material can include ametal complex.

According to another aspect of the present disclosure, a formulationcomprising a compound having a formula Ir(L_(A))_(n)(L_(B))_(3-n),having the structure:

is disclosed.

In Formula I, R_(a), R_(b), and R_(c) each independently representmono-, di-, tri-, tetra-substitution, or no substitution;

wherein X is O, S, or Se;

wherein n is an integer from 1 to 3;

wherein R_(a), R_(b), and R_(c) are each independently selected from thegroup consisting of hydrogen, deuterium, halide, alkyl, cycloalkyl,heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl,cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl,carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfanyl,sulfonyl, phosphino, and combinations thereof;

wherein R¹, R², R³, and R⁴ are each independently selected from thegroup consisting of hydrogen, deuterium, aryl, alkyl, cycloalkyl, andcombinations thereof;

wherein at least two of R¹, R², R³, and R⁴ are alkyl, cycloalkyl, orcombinations thereof; and

wherein any adjacent substitutions in R¹ to R⁴ and R_(a) to R_(c) areoptionally linked together to form a ring.

In some embodiments, the compound can be an emissive dopant in an OLED.In some embodiments, the compound can produce emissions viaphosphorescence, fluorescence, thermally activated delayed fluorescence,i.e., TADF (also referred to as E-type delayed fluorescence),triplet-triplet annihilation, or combinations of these processes.

Combination with Other Materials

The materials described herein as useful for a particular layer in anorganic light emitting device may be used in combination with a widevariety of other materials present in the device. For example, emissivedopants disclosed herein may be used in conjunction with a wide varietyof hosts, transport layers, blocking layers, injection layers,electrodes and other layers that may be present. The materials describedor referred to below are non-limiting examples of materials that may beuseful in combination with the compounds disclosed herein, and one ofskill in the art can readily consult the literature to identify othermaterials that may be useful in combination.

HIL/HTL:

A hole injecting/transporting material to be used in the presentinvention is not particularly limited, and any compound may be used aslong as the compound is typically used as a hole injecting/transportingmaterial. Examples of the material include, but are not limited to: aphthalocyanine or porphyrin derivative; an aromatic amine derivative; anindolocarbazole derivative; a polymer containing fluorohydrocarbon; apolymer with conductivity dopants; a conducting polymer, such asPEDOT/PSS; a self-assembly monomer derived from compounds such asphosphonic acid and silane derivatives; a metal oxide derivative, suchas MoO_(x); a p-type semiconducting organic compound, such as1,4,5,8,9,12-Hexaazatriphenylenehexacarbonitrile; a metal complex, and across-linkable compound.

Examples of aromatic amine derivatives used in HIL or HTL include, butare not limited to the following general structures:

Each of Ar¹ to Ar⁹ is selected from the group consisting of aromatichydrocarbon cyclic compounds such as benzene, biphenyl, triphenyl,triphenylene, naphthalene, anthracene, phenalene, phenanthrene,fluorene, pyrene, chrysene, perylene, and azulene; the group consistingof aromatic heterocyclic compounds such as dibenzothiophene,dibenzofuran, dibenzoselenophene, furan, thiophene, benzofuran,benzothiophene, benzoselenophene, carbazole, indolocarbazole,pyridylindole, pyrrolodipyridine, pyrazole, imidazole, triazole,oxazole, thiazole, oxadiazole, oxatriazole, dioxazole, thiadiazole,pyridine, pyridazine, pyrimidine, pyrazine, triazine, oxazine,oxathiazine, oxadiazine, indole, benzimidazole, indazole, indoxazine,benzoxazole, benzisoxazole, benzothiazole, quinoline, isoquinoline,cinnoline, quinazoline, quinoxaline, naphthyridine, phthalazine,pteridine, xanthene, acridine, phenazine, phenothiazine, phenoxazine,benzofuropyridine, furodipyridine, benzothienopyridine,thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine;and the group consisting of 2 to 10 cyclic structural units which aregroups of the same type or different types selected from the aromatichydrocarbon cyclic group and the aromatic heterocyclic group and arebonded to each other directly or via at least one of oxygen atom,nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom,chain structural unit and the aliphatic cyclic group. Wherein each Ar isfurther substituted by a substituent selected from the group consistingof hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl,arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl,heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylicacids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl,phosphino, and combinations thereof.

In one aspect, Ar¹ to Ar⁹ is independently selected from the groupconsisting of:

wherein k is an integer from 1 to 20; X¹⁰¹ to X¹⁰⁸ is C (including CH)or N; Z¹⁰¹ is NAr¹, O, or S; Ar¹ has the same group defined above.

Examples of metal complexes used in HIL or HTL include, but are notlimited to the following general formula:

wherein Met is a metal, which can have an atomic weight greater than 40;(Y¹⁰¹-Y¹⁰²) is a bidentate ligand, Y¹⁰¹ and Y¹⁰² are independentlyselected from C, N, O, P, and S; L¹⁰¹ is an ancillary ligand; k′ is aninteger value from 1 to the maximum number of ligands that may beattached to the metal; and k′+k″ is the maximum number of ligands thatmay be attached to the metal.

In one aspect, (Y¹⁰¹-Y¹⁰²) is a 2-phenylpyridine derivative. In anotheraspect, (Y¹⁰¹-Y¹⁰²) is a carbene ligand. In another aspect, Met isselected from Ir, Pt, Os, and Zn. In a further aspect, the metal complexhas a smallest oxidation potential in solution vs. Fc⁺/Fc couple lessthan about 0.6 V.

Host:

The light emitting layer of the organic EL device of the presentinvention preferably contains at least a metal complex as light emittingmaterial, and may contain a host material using the metal complex as adopant material. Examples of the host material are not particularlylimited, and any metal complexes or organic compounds may be used aslong as the triplet energy of the host is larger than that of thedopant. While the Table below categorizes host materials as preferredfor devices that emit various colors, any host material may be used withany dopant so long as the triplet criteria is satisfied.

Examples of metal complexes used as host are preferred to have thefollowing general formula:

wherein Met is a metal; (Y¹⁰³-Y¹⁰⁴) is a bidentate ligand, Y¹⁰³ and Y¹⁰⁴are independently selected from C, N, O, P, and S; L¹⁰¹ is an anotherligand; k′ is an integer value from 1 to the maximum number of ligandsthat may be attached to the metal; and k′+k″ is the maximum number ofligands that may be attached to the metal.

In one aspect, the metal complexes are:

wherein (O—N) is a bidentate ligand, having metal coordinated to atoms Oand N.

In another aspect, Met is selected from Ir and Pt. In a further aspect,(Y¹⁰³-Y¹⁰⁴) is a carbene ligand.

Examples of organic compounds used as host are selected from the groupconsisting of aromatic hydrocarbon cyclic compounds such as benzene,biphenyl, triphenyl, triphenylene, naphthalene, anthracene, phenalene,phenanthrene, fluorene, pyrene, chrysene, perylene, and azulene; thegroup consisting of aromatic heterocyclic compounds such asdibenzothiophene, dibenzofuran, dibenzoselenophene, furan, thiophene,benzofuran, benzothiophene, benzoselenophene, carbazole,indolocarbazole, pyridylindole, pyrrolodipyridine, pyrazole, imidazole,triazole, oxazole, thiazole, oxadiazole, oxatriazole, dioxazole,thiadiazole, pyridine, pyridazine, pyrimidine, pyrazine, triazine,oxazine, oxathiazine, oxadiazine, indole, benzimidazole, indazole,indoxazine, benzoxazole, benzisoxazole, benzothiazole, quinoline,isoquinoline, cinnoline, quinazoline, quinoxaline, naphthyridine,phthalazine, pteridine, xanthene, acridine, phenazine, phenothiazine,phenoxazine, benzofuropyridine, furodipyridine, benzothienopyridine,thienodipyridine, benzoselenophenopyridine, and selenophenodipyridine;and the group consisting of 2 to 10 cyclic structural units which aregroups of the same type or different types selected from the aromatichydrocarbon cyclic group and the aromatic heterocyclic group and arebonded to each other directly or via at least one of oxygen atom,nitrogen atom, sulfur atom, silicon atom, phosphorus atom, boron atom,chain structural unit and the aliphatic cyclic group. Wherein each groupis further substituted by a substituent selected from the groupconsisting of hydrogen, deuterium, halide, alkyl, cycloalkyl,heteroalkyl, arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl,cycloalkenyl, heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl,carboxylic acids, ester, nitrile, isonitrile, sulfanyl, sulfinyl,sulfonyl, phosphino, and combinations thereof.

In one aspect, the host compound contains at least one of the followinggroups in the molecule:

wherein R¹⁰¹ to R¹⁰⁷ is independently selected from the group consistingof hydrogen, deuterium, halide, alkyl, cycloalkyl, heteroalkyl,arylalkyl, alkoxy, aryloxy, amino, silyl, alkenyl, cycloalkenyl,heteroalkenyl, alkynyl, aryl, heteroaryl, acyl, carbonyl, carboxylicacids, ester, nitrile, isonitrile, sulfanyl, sulfinyl, sulfonyl,phosphino, and combinations thereof, when it is aryl or heteroaryl, ithas the similar definition as Ar's mentioned above. k is an integer from0 to 20 or 1 to 20; k′″ is an integer from 0 to 20. X¹⁰¹ to X¹⁰⁸ isselected from C (including CH) or N. Z¹⁰¹ and Z¹⁰² is selected fromNR¹⁰¹, O, or S.HBL:

A hole blocking layer (HBL) may be used to reduce the number of holesand/or excitons that leave the emissive layer. The presence of such ablocking layer in a device may result in substantially higherefficiencies as compared to a similar device lacking a blocking layer.Also, a blocking layer may be used to confine emission to a desiredregion of an OLED.

In one aspect, compound used in HBL contains the same molecule or thesame functional groups used as host described above.

In another aspect, compound used in HBL contains at least one of thefollowing groups in the molecule:

wherein k is an integer from 1 to 20; L¹⁰¹ is an another ligand, k′ isan integer from 1 to 3.ETL:

Electron transport layer (ETL) may include a material capable oftransporting electrons. Electron transport layer may be intrinsic(undoped), or doped. Doping may be used to enhance conductivity.Examples of the ETL material are not particularly limited, and any metalcomplexes or organic compounds may be used as long as they are typicallyused to transport electrons.

In one aspect, compound used in ETL contains at least one of thefollowing groups in the molecule:

wherein R¹⁰¹ is selected from the group consisting of hydrogen,deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy,aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl,aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile,isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinationsthereof, when it is aryl or heteroaryl, it has the similar definition asAr's mentioned above. Ar¹ to Ar³ has the similar definition as Ar'smentioned above. k is an integer from 1 to 20. X¹⁰¹ to X¹⁰⁸ is selectedfrom C (including CH) or N.

In another aspect, the metal complexes used in ETL include, but are notlimited to the following general formula:

wherein (O—N) or (N—N) is a bidentate ligand, having metal coordinatedto atoms O, N or N, N; L¹⁰¹ is another ligand; k′ is an integer valuefrom 1 to the maximum number of ligands that may be attached to themetal.

In any above-mentioned compounds used in each layer of the OLED device,the hydrogen atoms can be partially or fully deuterated. Thus, anyspecifically listed substituent, such as, without limitation, methyl,phenyl, pyridyl, etc. encompasses undeuterated, partially deuterated,and fully deuterated versions thereof. Similarly, classes ofsubstituents such as, without limitation, alkyl, aryl, cycloalkyl,heteroaryl, etc. also encompass undeuterated, partially deuterated, andfully deuterated versions thereof.

In addition to and/or in combination with the materials disclosedherein, many hole injection materials, hole transporting materials, hostmaterials, dopant materials, exciton/hole blocking layer materials,electron transporting and electron injecting materials may be used in anOLED. Non-limiting examples of the materials that may be used in an OLEDin combination with materials disclosed herein are listed in Table Abelow. Table A lists non-limiting classes of materials, non-limitingexamples of compounds for each class, and references that disclose thematerials.

TABLE A MATERIAL EXAMPLES OF MATERIAL PUBLICATIONS Hole injectionmaterials Phthalocyanine and porphyrin compounds

Appl. Phys. Lett. 69, 2160 (1996) Starburst triarylamines

J. Lumin. 72-74, 985 (1997) CF_(x) Fluorohydrocarbon

CH_(x)F_(y)

_(n) Appl. Phys. Lett. 78, polymer 673 (2001) Conducting polymers (e.g.,PEDOT:PSS, polyaniline, polythiophene)

Synth. Met. 87, 171 (1997) WO2007002683 Phosphonic acid and silane SAMs

US20030162053 Triarylamine or polythiophene polymers with conductivitydopants

EP1725079A1

Organic compounds with conductive inorganic compounds, such asmolybdenum and tungsten oxides

US20050123751 SID Symposium Digest, 37, 923 (2006) WO2009018009 n-typesemiconducting organic complexes

US20020158242 Metal organometallic complexes

US20060240279 Cross-linkable compounds

US20080220265 Polythiophene based polymers and copolymers

WO 2011075644 EP2350216 Hole transporting materials Triarylamines (e.g.,TPD, α-NPD)

Appl. Phys. Lett. 51, 913 (1987)

U.S. Pat. No. 5,061,569

EP650955

J. Mater. Chem. 3, 319 (1993)

Appl. Phys. Lett. 90, 183503 (2007)

Appl. Phys. Lett. 90, 183503 (2007) Triarylamine on spirofluorene core

Synth. Met. 91, 209 (1997) Arylamine carbazole compounds

Adv. Mater. 6, 677 (1994), US20080124572 Triarylamine with(di)benzothiophene/ (di)benzofuran

US20070278938, US20080106190 US20110163302 Indolocarbazoles

Synth. Met. 111, 421 (2000) Isoindole compounds

Chem. Mater. 15, 3148 (2003) Metal carbene complexes

US20080018221 Phosphorescent OLED host materials Red hostsArylcarbazoles

Appl. Phys. Lett. 78, 1622 (2001) Metal 8-hydroxyquinolates (e.g., Alq₃,BAlq)

Nature 395, 151 (1998)

US20060202194

WO2005014551

WO2006072002 Metal phenoxybenzothiazole compounds

Appl. Phys. Lett. 90, 123509 (2007) Conjugated oligomers and polymers(e.g., polyfluorene)

Org. Electron. 1, 15 (2000) Aromatic fused rings

WO2009066779, WO2009066778, WO2009063833, US20090045731, US20090045730,WO2009008311, US20090008605, US20090009065 Zinc complexes

WO2010056066 Chrysene based compounds

WO2011086863 Green hosts Arylcarbazoles

Appl. Phys. Lett. 78, 1622 (2001)

US20030175553

WO2001039234 Aryltriphenylene compounds

US20060280965

US20060280965

WO2009021126 Poly-fused heteroaryl compounds

US20090309488 US20090302743 US20100012931 Donor acceptor type molecules

WO2008056746

WO2010107244 Aza-carbazole/DBT/DBF

JP2008074939

US20100187984 Polymers (e.g., PVK)

Appl. Phys. Lett. 77, 2280 (2000) Spirofluorene compounds

WO2004093207 Metal phenoxybenzooxazole compounds

WO2005089025

WO2006132173

JP200511610 Spirofluorene-carbazole compounds

JP2007254297

JP2007254297 Indolocarbazoles

WO2007063796

WO2007063754 5-member ring electron deficient heterocycles (e.g.,triazole, oxadiazole)

J. Appl. Phys. 90, 5048 (2001)

WO2004107822 Tetraphenylene complexes

US20050112407 Metal phenoxypyridine compounds

WO2005030900 Metal coordination complexes (e.g., Zn, Al withN{circumflex over ( )}N ligands)

US20040137268, US20040137267 Blue hosts Arylcarbazoles

Appl. Phys. Lett, 82, 2422 (2003)

US20070190359 Dibenzothiophene/Di- benzofuran-carbazole compounds

WO2006114966, US20090167162

US20090167162

WO2009086028

US20090030202, US20090017330

US20100084966 Silicon aryl compounds

US20050238919

WO2009003898 Silicon/Germanium aryl compounds

EP2034538A Aryl benzoyl ester

WO2006100298 Carbazole linked by non- conjugated groups

US20040115476 Aza-carbazoles

US20060121308 High triplet metal organometallic complex

U.S. Pat. No. 7,154,114 Phosphorescent dopants Red dopants Heavy metalporphyrins (e.g., PtOEP)

Nature 395, 151 (1998) Iridium(III) organometallic complexes

Appl. Phys. Lett. 78, 1622 (2001)

US20030072964

US20030072964

US20060202194

US20060202194

US20070087321

US20080261076 US20100090591

US20070087321

Adv. Mater. 19, 739 (2007)

WO2009100991

WO2008101842

U.S. Pat. No. 7,232,618 Platinum(II) organometallic complexes

WO2003040257

US20070103060 Osmium(III) complexes

Chem. Mater. 17, 3532 (2005) Ruthenium(II) complexes

Adv. Mater. 17, 1059 (2005) Rhenium (I), (II), and (III) complexes

US20050244673 Green dopants Iridium(III) organometallic complexes

Inorg. Chem. 40, 1704 (2001)

US20020034656

U.S. Pat. No. 7,332,232

US20090108737

WO2010028151

EP1841834B

US20060127696

US20090039776

U.S. Pat. No. 6,921,915

US20100244004

U.S. Pat. No. 6,687,266

Chem. Mater. 16, 2480 (2004)

US20070190359

US 20060008670 JP2007123392

WO2010086089, WO2011044988

Adv. Mater. 16, 2003 (2004)

Angew. Chem. Int. Ed. 2006, 45, 7800

WO2009050290

US20090165846

US20080015355

US20010015432

US20100295032 Monomer for polymeric metal organometallic compounds

U.S. Pat. No. 7,250,226, U.S. Pat. No. 7,396,598 Pt(II) organometalliccomplexes, including polydentate ligands

Appl. Phys. Lett. 86, 153505 (2005)

Appl. Phys. Lett. 86, 153505 (2005)

Chem. Lett. 34, 592 (2005)

WO2002015645

US20060263635

US20060182992 US20070103060 Cu complexes

WO2009000673

US20070111026 Gold complexes

Chem. Commun. 2906 (2005) Rhenium(III) complexes

Inorg. Chem. 42, 1248 (2003) Osmium(II) complexes

U.S. Pat. No. 7,279,704 Deuterated organometallic complexes

US20030138657 Organometallic complexes with two or more metal centers

US20030152802

U.S. Pat. No. 7,090,928 Blue dopants Iridium(III) organometalliccomplexes

WO2002002714

WO2006009024

US20060251923 US20110057559 US20110204333

U.S. Pat. No. 7,393,599, WO2006056418, US20050260441, WO2005019373

U.S. Pat. No. 7,534,505

WO2011051404

U.S. Pat. No. 7,445,855

US20070190359, US20080297033 US20100148663

U.S. Pat. No. 7,338,722

US20020134984

Angew. Chem. Int. Ed. 47, 4542 (2008)

Chem. Mater. 18, 5119 (2006)

Inorg. Chem. 46, 4308 (2007)

WO2005123873

WO2005123873

WO2007004380

WO2006082742 Osmium(II) complexes

U.S. Pat. No. 7,279,704

Organometallics 23, 3745 (2004) Gold complexes

Appl. Phys. Lett. 74, 1361 (1999) Platinum(II) complexes

WO2006098120, WO2006103874 Pt tetradentate complexes with at least onemetal- carbene bond

U.S. Pat. No. 7,655,323 Exciton/hole blocking layer materialsBathocuproine compounds (e.g., BCP, BPhen)

Appl. Phys. Lett. 75, 4 (1999)

Appl. Phys. Lett. 79, 449 (2001) Metal 8-hydroxyquinolates (e.g., BAlq)

Appl. Phys. Lett. 81, 162 (2002) 5-member ring electron deficientheterocycles such as triazole, oxadiazole, imidazole, benzoimidazole

Appl. Phys. Lett. 81, 162 (2002) Triphenylene compounds

US20050025993 Fluorinated aromatic compounds

Appl. Phys. Lett. 79, 156 (2001) Phenothiazine-S-oxide

WO2008132085 Silylated five-membered nitrogen, oxygen, sulfur orphosphorus dibenzoheterocycles

WO2010079051 Aza-carbazoles

US20060121308 Electron transporting materials Anthracene- benzoimidazolecompounds

WO2003060956

US20090179554 Aza triphenylene derivatives

US20090115316 Anthracene-benzothiazole compounds

Appl. Phys. Lett. 89, 063504 (2006) Metal 8-hydroxyquinolates (e.g.,Alq₃, Zrq₄)

Appl. Phys. Lett. 51, 913 (1987) U.S. Pat. No. 7,230,107 Metalhydroxybenzoquinolates

Chem. Lett. 5, 905 (1993) Bathocuproine compounds such as BCP, BPhen,etc

Appl. Phys. Lett. 91, 263503 (2007)

Appl. Phys. Lett. 79, 449 (2001) 5-member ring electron deficientheterocycles (e.g., triazole, oxadiazole, imidazole, benzoimidazole)

Appl. Phys. Lett. 74, 865 (1999)

Appl. Phys. Lett. 55, 1489 (1989)

Jpn. J. Apply. Phys. 32, L917 (1993) Silole compounds

Org. Electron. 4, 113 (2003) Arylborane compounds

J. Am. Chem. Soc. 120, 9714 (1998) Fluorinated aromatic compounds

J. Am. Chem. Soc. 122, 1832 (2000) Fullerene (e.g., C60)

US20090101870 Triazine complexes

US20040036077 Zn (N{circumflex over ( )}N) complexes

U.S. Pat. No. 6,528,187

The present disclosure describes novel iridium complexes comprisingdialkyl-substituted aza-DBF and 2-phenylpyridine ligands. The dialkylsubstitution appears to improve OLED device performance such as CIEcolor and extending the lifetime.

Molecular modification of iridium complexes can effectively changematerial device performance. In this disclosure, the inventorsdiscovered that aza-DBF ligand with multi-alkyl-substitution on DBF ringon heteroleptic iridium complex can improve the device lifetime andcolor CIE. The improved color CIE was unexpected. It was found that inmany cases when methyl group is in R₁ position the color CIE of theparticular compound is always slightly red shifted compared to thenon-substituted compounds (e.g. R₁ is hydrogen).

DEVICE EXAMPLES

All example devices were fabricated by high vacuum (<10⁻⁷ Torr) thermalevaporation. The anode electrode is 1200 Å of indium tin oxide (ITO).The cathode consisted of 10 Å of LiF followed by 1,000 Å of Al. Alldevices were encapsulated with a glass lid sealed with an epoxy resin ina nitrogen glove box (<1 ppm of H₂O and O₂) immediately afterfabrication, and a moisture getter was incorporated inside the package.The organic stack of the device examples consisted of sequentially, fromthe ITO surface, 100 Å of LG-101 (available from LG Chem. Inc.) as thehole injection layer (HIL), 450 Å of Compound D as the hole transportinglayer (HTL), 400 Å of the invention compound doped in Compound B as hostwith 10 or 15 weight percent of the iridium phosphorescent compound asthe emissive layer (EML), 50 {acute over (Å)} of Compound C as ablocking layer (BL), 450 Å of Alq (tris-8-hydroxyquinoline aluminum) asthe ETL. The comparative Example with Compound A was fabricatedsimilarly to the Device Examples. The device results and data aresummarized in Tables 1 and 2. As used herein, Alq, Compounds A, B, C andD have the following structures:

TABLE 1 Device Structures of Inventive Compound and Comparative CompoundDevice HIL HTL EML (300 Å, doping %) BL ETL Comparative LG-101 CompoundD Compound Compound A Compound C Alq Example 1 100 Å 300 Å B as host 10%50 Å 450 Å Comparative LG-101 Compound D Compound Compound A Compound CAlq Example 2 100 Å 300 Å B as host 15% 50 Å 450 Å Inventive LG-101Compound D Compound Compound 1 Compound C Alq Example 1 100 Å 300 Å B ashost 10% 50 Å 450 Å Inventive LG-101 Compound D Compound Compound 1Compound C Alq Example 2 100 Å 300 Å B as host 15% 50 Å 450 Å InventiveLG-101 Compound D Compound Compound 2 Compound C Alq Example 3 100 Å 300Å B as host 10% 50 Å 450 Å Inventive LG-101 Compound D Compound Compound2 Compound C Alq Example 4 100 Å 300 Å B as host 15% 50 Å 450 Å

TABLE 2 VTE Device Results λmax FWHM Dopant Device x y (nm) (nm) (%)Comparative Example 1 0.337 0.630 528 59 10 (Dopant Compound A)Comparative Example 2 0.344 0.627 530 60 15 (Dopant Compound A)Inventive Example 1 0.310 0.640 520 61 10 (Dopant Compound 1) InventiveExample 2 0.315 0.638 520 63 15 (Dopant Compound 1) Inventive Example 30.332 0.632 526 60 10 (Dopant Compound 2) Inventive Example 4 0.3390.628 528 61 15 (Dopant Compound 2)

Table 2 is the summary of EL of comparative and inventive devices at1000 nits. The emission wavelengths of invention Compound 1 and Compound2 emission peak max with doping concentration at 10% were 520 nm and 526nm. Compared to the comparative Compound A, which exhibited emissionpeak max of 528 nm at 10% doping concentration, the inventive compoundsblue shifted about 8 and 2 nm, respectively. Similarly, the emissionwavelengths of invention Compound 1 and Compound 2 at dopingconcentration of 15% were 520 nm and 528 nm, respectively, whereas thecomparative Compound A exhibited emission peak max of 530 nm. Thus, theemission wavelengths of the inventive compounds blue shifted at 15%doping concentration also. The device results demonstrate thatmulti-alkylation can result in blue shift of emission spectrum which isa desired property for OLED device.

Synthesis Example 1 for an Example of the Novel Compound, CompoundIrL_(A8)(L_(B1))₂

An iridium precursor (1.69 g, 2.368 mmol) and2,4-bis(methyl-d₃)-8-(pyridin-2-yl)benzofuro[2,3-b]pyridine (0.996 g,3.55 mmol) were added to a 100 mL round-bottom flask equipped with amagnetic stir bar. Anhydrous DMF (25 mL) and 2-ethoxyethanol (25 mL)were added to the reaction mixture. The reaction flask was then placedinto an oil bath and gradually heated to 130° C. for 16 hours. Then, thereaction mixture was concentrated in a vacuum. The residue was thendissolved in CH₂Cl₂, filtered through a pad of Celite, eluting withCH₂Cl₂ and EtOAc, and concentrated in a vacuum. The crude product waspurified via flash chromatography on a (2×120) g column (CH₂Cl₂) toprovide Compound IrL_(A8)(L_(B1))₂ as an orange powder (0.77 g, 41%).

Synthesis Example 2 for an Example of the Novel Compound, CompoundIrL_(A7)(L_(B1))₂

An iridium precursor (1.85 g, 2.59 mmol) and2,3-bis(methyl-d₃)-8-(pyridin-2-yl)benzofuro[2,3-b]pyridine (1.09 g,3.89 mmol) were added to a 100 mL round-bottom flask equipped with amagnetic stir bar. Anhydrous DMF (26 mL) and 2-ethoxyethanol (26 mL)were added to the reaction mixture. The reaction flask was then placedinto an oil bath, gradually heated to 130° C. for 16 hours. Then, thereaction mixture was concentrated in a vacuum. The residue was thendissolved in CH₂Cl₂, filtered through a pad of celite, eluting withCH₂Cl₂ and EtOAc, and concentrated in a vacuum. The crude product waspurified via flash chromatography on a (2×220) g column (CH₂Cl₂) toprovide Compound IrL_(A7)(L_(B1))₂ as an orange solid (1.0 g, 49%).

Synthesis Example 3 for an Example of the Novel Compound, CompoundIrL_(A9)(L_(B1))₂

A mixture of iridium precursor (2.1 g, 2.94 mmol), aza dibenzofuranpyridine ligand (1.485 g, 5.3 mmol), 2-ethoxyethanol (30 mL) and DMF (30mL) was heated at 130° C. for 18 hours. The reaction mixture wasconcentrated to remove solvents and filtered through a small plug ofsilica gel and further chromatographed to give 1.2 g of CompoundIrL_(A9)(L_(B1))₂ (52.3% yield).

Synthesis Example 4 for an Example of the Novel Compound, CompoundIrL_(A9)(L_(B12))₂

A mixture of iridium precursor (2.3 g, 2.94 mmol), aza dibenzofuranpyridine ligand (1.485 g, 5.29 mmol), 2-ethoxyethanol (30 mL) and DMF(30 mL) was heated at 130° C. for 18 hours. The reaction mixture wasconcentrated to remove solvents and filtered through a small plug ofsilica gel and further chromatographed to give 0.47 g of CompoundIrL_(A9)(L_(B12))₂ (18.8% yield).

Synthesis Example 5 for an Example of the Novel Compound, CompoundIrL_(A81)(L_(B1))₂

A mixture of iridium precursor (1.35 g, 1.89 mmol), aza dibenzofuranpyridine ligand (0.935 g, 2.84 mmol), 2-ethoxyethanol (30 mL) and DMF(30 mL) was heated at 130° C. for 18 hours. The reaction mixture wasconcentrated to remove solvents and filtered through a small plug ofsilica gel and further chromatographed to give 0.77 g of CompoundIrL_(A81)(L_(B1))₂ (49.1% yield).

Synthesis Example 6 for an Example of the Novel Compound, CompoundIrL_(A81)(L_(B9))₂

A mixture of iridium precursor (2.1 g, 2.001 mmol), aza dibenzofuranpyridine ligand (0.991 g, 3.01 mmol), 2-ethoxyethanol (30 mL) and DMF(30 mL) was heated at 130° C. for 18 hours. The reaction mixture wasconcentrated to remove solvents and filtered through a small plug ofsilica gel and further chromatographed to give 0.86 g of CompoundIrL_(A81)(L_(B9))₂ (49.7% yield).

Synthesis Example 7 for an Example of the Novel Compound, CompoundIrL_(A80)(L_(B9))₂

A mixture of iridium precursor (0.93 g, 1.23 mmol), aza dibenzofuranpyridine ligand (0.608 g, 1.845 mmol), 2-ethoxyethanol (13 mL) and DMF(13 mL) was heated at 130° C. for 19 hours. The reaction mixture wasconcentrated to remove solvents and filtered through a small plug ofsilica gel and further chromatographed to give 0.43 g of CompoundIrL_(A80)(L_(B9))₂ (40.5% yield).

It is understood that the various embodiments described herein are byway of example only, and are not intended to limit the scope of theinvention. For example, many of the materials and structures describedherein may be substituted with other materials and structures withoutdeviating from the spirit of the invention. The present invention asclaimed may therefore include variations from the particular examplesand preferred embodiments described herein, as will be apparent to oneof skill in the art. It is understood that various theories as to whythe invention works are not intended to be limiting.

What is claimed is:
 1. A compound having the formulaIr(L_(A))_(n)(L_(B))_(3-n), having the structure:

wherein R_(a), R_(b), and R_(c) each independently represent mono-, di-,tri-, tetra-substitution, or no substitution; wherein X is O, S, or Se;wherein n is an integer from 1 to 3; wherein R_(a), R_(b), and R_(c) areeach independently selected from the group consisting of hydrogen,deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy,aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl,aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile,isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinationsthereof; wherein (i) R¹ and R⁴ are each independently selected from thegroup consisting of alkyl, cycloalkyl, and combinations thereof, whereineach group is optionally partially or fully deuterated, and R² and R³are hydrogen, or (ii) R¹, R³, and R⁴ are each independently selectedfrom the group consisting of alkyl, cycloalkyl, and combinationsthereof, wherein each group is optionally partially or fully deuteratedand R² is hydrogen; and wherein any two substituents among R_(a) toR_(c) or R³ and R⁴ in option (ii) are optionally linked together to forma ring.
 2. The compound of claim 1, wherein, when R¹, R³, and R⁴ arealkyl or cycloalkyl, each is independently selected from the groupconsisting of methyl, ethyl, propyl, 1-methylethyl, butyl,1-methylpropyl, 2-methylpropyl, pentyl, 1-methylbutyl, 2-methylbutyl,3-methylbutyl, 1,1-dimethylpropyl, 1,2-dimethylpropyl,2,2-dimethylpropyl, cyclopentyl, cyclohexyl, and combinations thereof,wherein each group is optionally partially or fully deuterated.
 3. Thecompound of claim 1, wherein n is
 1. 4. The compound of claim 1, whereinX is O.
 5. The compound of claim 1, wherein R¹ and R⁴ are eachindependently selected from the group consisting of alkyl, cycloalkyl,and combinations thereof, wherein each group is optionally partially orfully deuterated, and R² and R³ are hydrogen.
 6. The compound of claim1, wherein R¹, R³, and R⁴ are each independently selected from the groupconsisting of alkyl, cycloalkyl, and combinations thereof, wherein eachgroup is optionally partially or fully deuterated and R² is hydrogen. 7.The compound of claim 1, wherein the total carbon number of R¹, R², R³,and R⁴ are at least
 3. 8. The compound of claim 1, wherein R_(a), R_(b),and R_(c) are each independently selected from the group consisting ofhydrogen, deuterium, alkyl, cycloalkyl, aryl, heteroaryl, andcombinations thereof.
 9. The compound of claim 1, wherein L_(A) has astructure according to the following formula:

and is selected from the group consisting of L_(A1), L_(A1), L_(A9),L_(A15), L_(A21), L_(A27), L_(A33), L_(A39), L_(A45), L_(A51), L_(A57),L_(A63), L_(A69), L_(A75), L_(A81), L_(A87), L_(A93), L_(A100),L_(A106), L_(A109), L_(A110), L_(A113), L_(A122), L_(A123), L_(A124),L_(A133), L_(A139), L_(A145), L_(A151), L_(A157), L_(A163), L_(A169),L_(A175), L_(A181), L_(A187), L_(A1193), L_(A205), L_(A211), L_(A217),L_(A223), L_(A229), L_(A237), L_(A238), L_(A242), L_(A245), L_(A248),L_(A250), L_(A255), L_(A256), L_(A260), L_(A263), L_(A266), L_(A273),L_(A274), L_(A278), L_(A281), L_(A284), L_(A286), L_(A291), L_(A292),L_(A296), L_(A299), L_(A304), L_(A305), L_(A308), L_(A312), L_(A314),L_(A315), L_(A317), L_(A321)-L_(A339), L_(A343)-L_(A351), L_(A359),L_(A363), L_(A368), L_(A372), L_(A377), L_(A381), L_(A386), L_(A390),L_(A393), L_(A396), L_(A402), L_(A408), L_(A415), L_(A421), L_(A427),L_(A431) and L_(A434)-L_(A438), wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷, andR⁸ are as defined in Tables 1A and 1B shown below: TABLE 1A Ligand L_(A)R¹ R² R³ R⁴ R⁵ R⁶ R⁷ R⁸ L_(A3) CH₃ H H CH₃ H H H H L_(A9) CD₃ H H CD₃ HH H H L_(A15) CH₃ H H CH₃ CH₃ H H H L_(A21) CD₃ H H CD₃ CD₃ H H HL_(A27) CH₃ H H CH₃ H CH₃ H H L_(A33) CD₃ H H CD₃ H CD₃ H H L_(A39) CH₃H H CH₃ H H CH₃ H L_(A45) CD₃ H H CD₃ H H CD₃ H L_(A51) CH₃ H H CH₃ H HH CH₃ L_(A57) CD₃ H H CD₃ H H H CD₃ L_(A63) CH₃ H H CH₃ CH(CH₃)₂ H H HL_(A69) CD₃ H H CD₃ CD(CD₃)₂ H H H L_(A75) CH₃ H H CH₃ H CH(CH₃)₂ H HL_(A81) CD₃ H H CD₃ H CD(CD₃)₂ H H L_(A87) CH₃ H H CH₃ H H CH(CH₃)₂ HL_(A93) CD₃ H H CD₃ H H CD(CD₃)₂ H L_(A100) CH₂CH₃ H H CH₃ H CH(CH₃)₂ HH L_(A106) CH₃ H H CH₂CH₃ H CH(CH₃)₂ H H L_(A109) CD₂CD₃ H H CD₃ HCD(CD₃)₂ H H L_(A110) CD₂CD₃ H H CD₃ H CD(CH₃)₂ H H L_(A113) CH₂CH₃ H HCH₃ H H CH(CH₃)₂ H L_(A119) CH₃ H H CH₂CH₃ H H CH(CH₃)₂ H L_(A122)CD₂CD₃ H H CD₃ H H CD(CD₃)₂ H L_(A123) CD₃ H H CD₂CH₃ H H CD(CH₃)₂ HL_(A124) CD₃ H H CD₂CH₃ H H H CD₃ L_(A127) CH₃ H H CH₃ H H H CH(CH₃)₂L_(A133) CD₃ H H CD₃ H H H CD(CD₃)₂ L_(A139) CH₃ H H CH₃ H CH₂CH(CH₃)₂ HH L_(A145) CD₃ H H CD₃ H CD₂CH(CH₃)₂ H H L_(A151) CH₃ H H CH₃ H HCH₂CH(CH₃)₂ H L_(A157) CD₃ H H CD₃ H H CD₂CH(CH₃)₂ H L_(A163) CH₃ H HCH₃ CH₃ CH₃ H H L_(A169) CD₃ H H CD₃ CD₃ CD₃ H H L_(A175) CH₃ H H CH₃ HCH₃ CH₃ H L_(A181) CD₃ H H CD₃ H CD₃ CD₃ H L_(A187) CH₃ H H CH₃ HCH(CH₃)₂ CH₃ H L_(A193) CD₃ H H CD₃ H CD(CD₃)₂ CD₃ H L_(A199) CH₃ H HCH₃ H CH₃ CH(CH₃)₂ H L_(A205) CD₃ H H CD₃ H CD₃ CD(CD₃)₂ H L_(A211) CH₃H H CH₃ H CH₂CH(CH₃)₂ CH₃ H L_(A217) CD₃ H H CD₃ H CD₂CH(CH₃)₂ CD₃ HL_(A223) CH₃ H H CH₃ H CH₃ CH₂CH(CH₃)₂ H L_(A229) CD₃ H H CD₃ H CD₃CD₂CH(CH₃)₂ H L_(A237) CH(CH₃)₂ H H CH₃ H H H H L_(A238) CH₃ H HCH(CH₃)₂ H H H H L_(A242) CH(CH₃)₂ H H CH(CH₃)₂ H H H H L_(A245)CD(CH₃)₂ H H CD₃ H H H H L_(A248) CD₃ H H CD(CH₃)₂ H H H H L_(A250)CD(CH₃)₂ H H CD(CH₃)₂ H H H H L_(A255) CH(CH₃)₂ H H CH₃ H CH(CH₃)₂ H HL_(A256) CH₃ H H CH(CH₃)₂ H CH(CH₃)₂ H H L_(A260) CH(CH₃)₂ H H CH(CH₃)₂H CH(CH₃)₂ H H L_(A263) CD(CH₃)₂ H H CD₃ H CD(CD₃)₂ H H L_(A266) CD₃ H HCD(CH₃)₂ H CD(CD₃)₂ H H L_(A268) CD(CH₃)₂ H H CD(CH₃)₂ H CD(CD₃)₂ H HL_(A273) CH(CH₃)₂ H H CH₃ H CH₃ CH(CH₃)₂ H L_(A274) CH₃ H H CH(CH₃)₂ HCH₃ CH(CH₃)₂ H L_(A278) CH(CH₃)₂ H H CH(CH₃)₂ H CH₃ CH(CH₃)₂ H L_(A281)CD(CH₃)₂ H H CD₃ H CD₃ CH(CH₃)₂ H L_(A284) CD₃ H H CD(CH₃)₂ H CD₃CH(CH₃)₂ H L_(A286) CD(CH₃)₂ H H CD(CH₃)₂ H CD₃ CH(CH₃)₂ H L_(A291)CH(CH₃)₂ H H CH₃ H CH(CH₃)₂ CH₃ H L_(A292) CH₃ H H CH(CH₃)₂ H CH(CH₃)₂CH₃ H L_(A296) CH(CH₃)₂ H H CH(CH₃)₂ H CD(CH₃)₂ CH₃ H L_(A299) CD(CH₃)₂H H CD₃ H CD(CH₃)₂ CD₃ H L_(A302) CD₃ H H CD(CH₃)₂ H CD(CH₃)₂ CD₃ HL_(A304) CD(CH₃)₂ H H CD(CH₃)₂ H CD(CH₃)₂ CD₃ H L_(A305) CD(CH₃)₂ H HCD(CH₃)₂ H CD(CD₃)₂ CD₃ H L_(A308) CD₃ H H CD₃ H CD(CH₃)₂ H H L_(A312)CH₃ CH₃ CH₃ CH₃ H H H H L_(A314) CH₃ H CH₃ CH₃ H H H H L_(A315) H CH₃CH₃ CH₃ H H H H L_(A317) CD₃ H CD₃ CD₃ H H H H L_(A321) CD₃ H CD₃ CD₃ HCD(CD₃)₂ H H L_(A322) CD₃ H CD₃ CD₃ H H CD(CD₃)₂ H L_(A323) CD₃ H CD₃CD₃ H CD(CD₃)₂ CD₃ H L_(A324) CD₃ H CD₃ CD₃ H CD₃ CD(CD₃)₂ H L_(A325)CD₃ H CD₃ CD(CH₃)₂ H H H H L_(A326) CD₃ H CD₃ CD(CH₃)₂ H CD(CD₃)₂ H HL_(A327) CD₃ H CD₃ CD(CH₃)₂ H H CD(CD₃)₂ H L_(A328) CD₃ H CD₃ CD(CH₃)₂ HCD(CD₃)₂ CD₃ H L_(A329) CD₃ H CD₃ CD(CH₃)₂ H CD₃ CD(CD₃)₂ H L_(A330) CD₃H CD(CH₃)₂ CD₃ H H H H L_(A331) CD₃ H CD(CH₃)₂ CD₃ H CD(CD₃)₂ H HL_(A332) CD₃ H CD(CH₃)₂ CD₃ H H CD(CD₃)₂ H L_(A333) CD₃ H CD(CH₃)₂ CD₃ HCD(CD₃)₂ CD₃ H L_(A334) CD₃ H CD(CH₃)₂ CD₃ H CD₃ CD(CD₃)₂ H L_(A335) CD₃H CD(CH₃)₂ CD(CH₃)₂ H H H H L_(A336) CD₃ H CD(CH₃)₂ CD(CH₃)₂ H CD(CD₃)₂H H L_(A337) CD₃ H CD(CH₃)₂ CD(CH₃)₂ H H CD(CD₃)₂ H L_(A338) CD₃ HCD(CH₃)₂ CD(CH₃)₂ H CD(CD₃)₂ CD₃ H L_(A339) CD₃ H CD(CH₃)₂ CD(CH₃)₂ HCD₃ CD(CD₃)₂ H L_(A343) CD(CH₃)₂ H CD₃ CD₃ H H H H L_(A344) CD(CH₃)₂ HCD₃ CD₃ H CD(CD₃)₂ H H L_(A345) CD(CH₃)₂ H CD₃ CD₃ H H CD(CD₃)₂ HL_(A346) CD(CH₃)₂ H CD₃ CD₃ H CD₃ CD(CD₃)₂ H L_(A347) CD(CH₃)₂ H CD₃ CD₃H CD(CD₃)₂ CD₃ H L_(A348) CD₃ H H CD(CH₃)₂ H CD(CD₃)₂ H H L_(A349) CD₃ HH CD(CH₃)₂ H H CD(CD₃)₂ H L_(A350) CD₃ H H CD(CH₃)₂ H CD(CD₃)₂ CD₃ HL_(A351) CD₃ H H CD(CH₃)₂ H CD₃ CD(CD₃)₂ H

TABLE 1B Ligand L_(A) R¹ R² R³ R⁴ R⁵ R⁶ R⁷ R⁸ L_(A359)

H H CH₃ H H H H L_(A363) CH₃ H H

H H H H L_(A368)

H H CD₃ H H H H L_(A372) CD₃ H H

H H H H L_(A377)

H H CH₃ H H H H L_(A381) CH₃ H H

H H H H L_(A386)

H H CD₃ H H H H L_(A390) CD₃ H H

H H H H L_(A393)

H H CH₃ H H CH3 H L_(A396)

H H CH₃ H CH(CH₃)₂ H H L_(A402)

H H CD₃ H CD(CD₃)₂ H H L_(A408)

H H CD₃ H CD(CH₃)₂ H H L_(A415)

H H CH₃ H CH(CH₃)₂ H H L_(A421)

H H CD₃ H CD(CD₃)₂ H H L_(A427)

H H CD₃ H CD(CH₃)₂ H H L_(A431) CD₃ H H

H CD(CH₃)₂ H H L_(A434)

H H

H CD(CH₃)₂ H H L_(A435)

H H

H CD(CH₃)₂ H H L_(A436)

H H

H CD(CH₃)₂ H H L_(A437)

H H

H CD(CH₃)₂ H H L_(A438)

H H

H CD(CH₃)₂ H H.


10. The compound of claim 1, wherein L_(B) is selected from the groupconsisting of:


11. The compound of claim 1, wherein the compound is selected from thegroup consisting of:


12. A device comprising one or more organic light emitting devices, atleast one of the one or more organic light emitting devices comprising:an anode; a cathode; and an organic layer, disposed between the anodeand the cathode, the organic layer comprising a compound having aformula Ir(L_(A))_(n)(L_(B))_(3-n), having the structure:

wherein R_(a), R_(b), and R_(c) each independently represent mono-, di-,tri-, tetra-substitution, or no substitution; wherein X is O, S, or Se;wherein n is an integer from 1 to 3; wherein R_(a), R_(b), and R_(c) areeach independently selected from the group consisting of hydrogen,deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy,aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl,aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile,isonitrile, sulfanyl, sulfinyl, sulfonyl, phosphino, and combinationsthereof; wherein (i) R¹ and R⁴ are each independently selected from thegroup consisting of alkyl, cycloalkyl, and combinations thereof, whereineach group is optionally partially or fully deuterated, and R² and R³are hydrogen, or (ii) R¹, R³, and R⁴ are each independently selectedfrom the group consisting of alkyl, cycloalkyl, and combinationsthereof, wherein each group is optionally partially or fully deuteratedand R² is hydrogen; and wherein any two substituents among R¹ to R⁴ andR_(a) to R_(c) are optionally linked together to form a ring.
 13. Thedevice of claim 12, wherein the device is selected from the groupconsisting of a consumer product, an electronic component module, anorganic light-emitting device, and a lighting panel.
 14. The device ofclaim 12, wherein the organic layer is an emissive layer and thecompound is an emissive dopant or a non-emissive dopant.
 15. The deviceof claim 12, wherein the organic layer further comprises a host; whereinthe host comprises a triphenylene containing benzo-fused thiophene orbenzo-fused furan; wherein any substituent in the host is an unfusedsubstituent independently selected from the group consisting ofC_(n)H_(2n+1), OC_(n)H_(2n+1), OAr₁, N(C_(n)H_(2n+1))₂, N(Ar₁)(Ar₂),CH═CH—C_(n)H_(2n+1), C≡CC_(n)H_(2n+1), Ar₁, Ar₁-Ar₂, C_(n)H_(2n)—Ar₁, orno substitution; wherein n is from 1 to 10; and wherein Ar₁ and Ar₂ areindependently selected from the group consisting of benzene, biphenyl,naphthalene, triphenylene, carbazole, and heteroaromatic analogsthereof.
 16. The device of claim 12, wherein the organic layer furthercomprises a host, wherein the host comprises at least one chemical groupselected from the group consisting of triphenylene, carbazole,dibenzothiphene, dibenzofuran, dibenzoselenophene, azatriphenylene,azacarbazole, aza-dibenzothiophene, aza-dibenzofuran, andaza-dibenzoselenophene.
 17. The device of claim 12, wherein the organiclayer further comprises a host and the host is selected from the groupconsisting of:

and combinations thereof.
 18. A formulation comprising a compound havinga formula Ir(L_(A))_(n)(L_(B))_(3-n), having the structure:

wherein R_(a), R_(b), and R_(c) each independently represent mono-, di-,tri-, tetra-substitution, or no substitution; wherein X is O, S, or Se;wherein n is an integer from 1 to 3; wherein R_(a), R_(b), and R_(c) areeach independently selected from the group consisting of hydrogen,deuterium, halide, alkyl, cycloalkyl, heteroalkyl, arylalkyl, alkoxy,aryloxy, amino, silyl, alkenyl, cycloalkenyl, heteroalkenyl, alkynyl,aryl, heteroaryl, acyl, carbonyl, carboxylic acids, ester, nitrile,isonitrile, sulfanyl, sulfanyl, sulfonyl, phosphino, and combinationsthereof; wherein (i) R¹ and R⁴ are each independently selected from thegroup consisting of alkyl, cycloalkyl, and combinations thereof, whereineach group is optionally partially or fully deuterated, and R² and R³are hydrogen, or (ii) R¹, R³, and R⁴ are each independently selectedfrom the group consisting of alkyl, cycloalkyl, and combinationsthereof, wherein each group is optionally partially or fully deuteratedand R² is hydrogen; and wherein any two substituents among R¹ to R⁴ andR_(a) to R_(c) are optionally linked together to form a ring.